JPS62115146A - Interlocking device for lens and mirror in variable power device - Google Patents

Abstract

PURPOSE:To vary the magnification continuously for zooming by providing a means, which moves a lens and an optical path converting mirror to each variable power position, to make complicated electronic control circuits and driving mechanisms unnecessary and driving continuously a device with a simple mechanism. CONSTITUTION:The first mirror unit 4 under an original platen 2 of a copying machine body 1 is fitted to a guide rail 9 and can be moved. The irradiated light from a light source member 7 of this unit 4 is reflected on the reflecting face of a frame body 6 to subject the surface of an original to sit exposure. The reflected light from the surface of the original is made incident on a copying lens 14 through the first and second mirrors 10 and 11 of a supporting member 12. The member 12 is fitted to the rail 9 and is movable in the direction of the optical axis similarly to the unit 4 to form the second mirror unit 13. The third mirror unit 17 consisting of the fourth mirror 15 and the fifth mirror 16 behind the lens 14 is made movable in the body 1 in accordance with the copy magnification, and the image inverted by the mirror 16 is carried to an image forming part 19 and is copied on photosensitive materials S.

Description

[Detailed Description of the Invention] [Scope of Industrial Application] The present invention relates to a variable magnification exposure optical device for an image recording device such as an electrophotographic copying machine, and more particularly to a device for moving optical system members accompanying unauthorized magnification changes. be.

[Conventional technology]

Generally, in image recording devices such as electrophotographic copying machines, a slit exposure scanning method is often adopted as a method of exposing an original image onto a sheet-like or cylindrical photoreceptor, in which the original is sequentially exposed from one end over a certain width. ing. In this case, two methods are available: an optical system movement method in which the exposure light source and part of the mirror group are moved to perform exposure scanning while the original that is not to be copied remains stationary, and an original movement method in which exposure scanning is performed while moving the original. method is used. Furthermore, electrophotographic copying machines have also appeared that are capable of both the above-mentioned optical system moving scanning and original moving methods.

Furthermore, recently, electrophotographic copying machines with a variable magnification function for enlarging and reducing original images have also been commercially available. The methods for performing this magnification change include: ■ A method of changing magnification using a zoom lens; ■ A method of changing magnification that changes the focal length of the lens by adding an attachment lens to the main lens; ■ Moving the lens and optical path length. There is a stepless zoom borrowing method that allows you to change the numbers at the same time.

[Problem that the invention seeks to solve]

When performing zoom magnification using the third method described above, the lens position and optical path length must be changed in a complicated manner, and in order to continuously change these and perform stepless zoom magnification, , the mechanism becomes complicated.

Recently, with the use of microcomputers, when changing the lens position and optical path length using the binary third method, a method has been developed in which the total amount of displacement is divided into 100 equal parts and the displacement of 100 steps is determined by computer control. Now I can get continuous zoom for practical purposes.

However, if all of these positional controls were to be performed using a microcomputer, in order to move and set the lens and mirror positions to predetermined positions, it would be necessary to digitally count the amount of movement using an encoder, etc., and compare it with the set value. It must be controlled and stopped using a feedback mechanism with high positional accuracy. Furthermore, the electric circuit becomes complicated to prevent noise signals during digital processing. This has the disadvantage that the entire control device becomes expensive.

[Means for solving problems]

SUMMARY OF THE INVENTION An object of the present invention is to provide a continuous zoom magnification device in which a simple mechanism connects and drives means for moving a lens and an optical path conversion mirror to each magnification changing position.

The variable magnification device for copying of the present invention constitutes a scanning optical system for image exposure by an exposure light source, a movable optical path conversion mirror and a lens, and moves the optical path conversion mirror and lens along the optical axis. The magnification changing device converts the copying magnification by moving the lens in the optical axis direction in proportion to the copying magnification. and a third moving means that moves the position of the optical path conversion mirror in response to the second moving means, and the third moving means moves the second moving means. a first rack provided on the member; a second rack provided on the member for moving the optical path length conversion mirror; a first pinion shaft that is rotated by engaging with the #1 rack; This is achieved by a lens-mirror interlocking device in a variable magnification device characterized by comprising a second pinion shaft that transmits rotation and is relatively movable in the axial direction to move the second rank.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a perspective view showing the main parts of a variable magnification device according to the present invention. FIG. 2 is a sectional view showing the overall configuration of the variable power device. The photosensitive materials used in this copying device include sheet-like or roll-like direct image-forming photosensitive materials, such as ebori versal type silver halide photosensitive materials (direct positive photographic paper, etc.) and photoconductive photosensitive materials. Paper, etc.

At the top of the main body 1 of the copying apparatus, there are disposed an original table 2 made of transparent glass on which a document tray is placed, and a platen cover 3 that covers the document tray after the document tray is placed on the document table 2.

A first mirror unit 4 is movably disposed within the main body 1 of the copying apparatus and below the document table 2. As shown in FIG. 1st above
The mirror unit 4 includes a support member 5 having a sliding portion that engages with a guide rail 9 to make the first mirror unit 4 movable, and a frame 6 fixed to the support member 5 and having a reflective curved surface.
, a tubular light source member (such as a halogen lamp) 7 whose both ends are held by contact holding members on the support member 5, and a first mirror 8. A slit portion 6A is provided in a part of the frame body 6.

-1- The light irradiated by the light source member 7 is reflected and condensed by the reflective surface of the frame 6 to expose the document surface to slit light.

The illumination light that exposed the document surface to the slit is reflected by the document surface, passes through the sulin 6A, enters the first mirror 8, is reflected, passes through the second mirror 10, 13 mirror 11, and
The light enters a copying lens 14, passes through a fourth mirror 15, a fifth mirror 16, a slit 18, and enters an image forming section 19.
A slit F image is formed on the photosensitive surface of the photosensitive material S located at .

The second mirror 10, the third mirror 11, and the support member 12 that holds these mirrors and fits into the guide rail,
A second mirror unit 13 is formed and is movable in the same direction as the first mirror unit 4.

The first mirror unit 4 is driven by a drive motor (not shown), slides on a guide rail 9, moves linearly to the right in the drawing, and optically scans the entire surface of the document tray.

The first mirror unit 4 operates at a speed related to the transport speed of the photosensitive material S, that is, the speed of the first mirror unit 4 is set at a speed related to the transport speed of the photosensitive material S. , when the copying magnification is M, the second mirror unit 13 is moved at a speed that satisfies V, xM=V, and the speed of 172 is 1/2.
2 and (1) both move linearly to the right parallel to the document table 2.

In FIG. 2, the @1 mirror unit 4 and the second mirror unit 2 13 indicated by broken lines on the right indicate the positions where the forward stroke of the slit exposure scan of the document surface has been completed.

On the other hand, from Kiren 7:14, the rear optical system members, that is, the main lens 14 and the third mirror unit 17 consisting of the fourth mirror 15 and the fifth mirror 16, are all movable according to the copying magnification. There is.

The image inverted by the t$5 mirror 16 forms a copy image on the photosensitive surface of the photosensitive material S, which is conveyed to the imaging section 19 through the slit 18. Here, the photosensitive material surface of the imaging section is a photographic material, such as a silver halide photographic material.

FIG. 3 is a diagram showing the configuration of the variable magnification optical system at the start of scanning, and FIG. 4 is a diagram illustrating the optical path length of the variable magnification optical system.

In FIG. 4, L o , L + , and L 2 indicate the positions of the main lens 14 at equal magnification, reduction, and enlargement, respectively;
A indicates each development angle on the object side from the entire surface of the main lens 14 to the document table 2. , A1, A2, and the development distances on the image plane side from the rear surface of the main lens 14 to the image forming plane of the photosensitive material S are B, respectively. , B I , B 2 and the thickness of the lens 14, the total optical path length is expressed by the following equation.

U, = A o1B, + Q u, = Al10B, +! 1=Uo+δχ1U 2 =A
2 + 82 + Q ” No ten δχ2 where, δ
χδχ2 is the total optical path length U during expansion and contraction, respectively.
, U2 and the total optical path length U0 at the same magnification.

FIG. 5 shows the optical path length A on the object side and the optical path length B on the image plane side.

and a diagram showing the relationship between the total optical path length U and the copying magnification, and the numerical values in the diagram are optical design data values in a specific example of a variable power optical system using a lens 14 with a focal length (f) of 200 au. .

As shown in the figure, a curve A indicating the object side optical path length A connects the optical path length A1 at an enlargement copying magnification of 1.55 and the optical path length A2 at a reduction copying magnification of 0.65. I am doing it. On the other hand, the image side optical path length B is the optical path length B1 at the enlargement copying magnification of 1.55 and the optical path length B1 at the reduction copying magnification of 0.6.
It is represented by a straight line connecting the optical path length B2 in 5. Further, the total optical path length U is the minimum distance U0, which is approximately four times the focal length of the lens 14 when copying at the same magnification, and when making the enlarged copy,
l. When the above-mentioned reduction copying is performed, it becomes U2, and a curve [J is drawn.

Next, the amount of movement of the lens 14 when performing variable magnification copying will be explained. The starting position of the lens 14 is now the minimum reduction copying magnification position L furthest from the document surface side.

``For convenience'' - explain.

Straight line B' in FIG. 5 is an auxiliary line added for convenience of explanation.

That is, the straight line B' is an auxiliary straight line drawn in the opposite direction at the same angle of inclination θ as the straight line B, with the point A1 indicating the object side optical path length at the time of minimum reduction copying as the base point.

The distance A(χ) between the lens 14 and the document table 2 at any copying magnification is expressed by the following equation.

A (χ) = A, - [ΔB (χ) + δ (χ)] where A1
is lens 1 at the minimum copying magnification (e.g. xo, 65)
4 and the document table 2. The value is constant at any distance.

Further, ΔB(χ) is the amount of proportional movement of the lens 14, which moves in proportion to an arbitrary magnification ratio. δ(χ) is a correction movement amount by which the lens 14 is corrected and moved for each magnification ratio.

Now, the amount of lens movement at an arbitrary copying magnification M(χ) will be explained using the diagram in FIG.

In the figure, the object side optical path length B(χ) at an arbitrary copying magnification M(χ) is the χ component of the point P of the direct M B-h, and is expressed by the following equation.

B(χ)-B, +ΔB(χ) This ΔB(χ) is equal to the χ component of the opening between point P' and point A on the line #ilB' with point A3 as the base point. This P'
If the intersection of the straight line connecting point P and curve A is Q and α, then the distance between P' and QNi is δ(χ).

This δ(χ) indicates a correction value for the amount of movement of the lens 14 at the copying magnification M(χ). That is, in order to form a copied image at the copying magnification M(χ), the lens 14 is moved from the position ffA of the minimum copying magnification (Xo, 65) to the proportional movement amount ΔB(χ).
If it is moved and stopped at the Q point position on the song #iA by moving it by the corrected movement amount δ(χ) and further moving it by a combined amount of correction movement δ(χ), imaging at the required copying magnification M(χ) can be obtained.

In addition, in FIG. 5, point R on the track gU is at the copying magnification M(
χ) shows the total party path length U(χ). ΔU(χ) represents the optical path length difference between the total path length tJ o during the same-magnification copying and the total path length during the variable-magnification copying. In FIG. 3, at the start of zooming, the optical system in front of the lens 14, that is, the first mirror 8. Second
Mirror 10. The third mirror 11 is in a stationary state, and when the magnification information is input, the lens 14 moves by the magnification proportional movement amount ΔB(
χ) and the magnification correction movement amount δ(χ) on the optical axis. At the same time, a third mirror unit 17, which is an integrated fourth mirror 15 and a fifth mirror 16,
It moves by half of the corrected movement amount δ(χ). After each member of the optical system is set in this state, scanning exposure for copying starts, and the first mirror 8 and second mirror unit 13 move and scan.

FIG. 1 is a perspective view showing the structure of an optical system member that performs the above-mentioned variable power setting.

A copying lens 7:14 is mounted and fixed on a movable table 22. The moving table 14 is a lens unit table 20.
It is fitted into the guide member 21 fixed to the optical axis direction (Y
direction).

Id members 24 and 25 that slidably hold the slide plate 23 are fixed to the upper surface of the lens unit table 20. This slide plate 23 has a linear groove 2.
3A is open, and a bottle 26 fixed to one end of the movable table 22 is fitted therein so as to be slidable therein.

By engaging the groove portion 23A with the bin 26, the movement of the slide plate 23 in the Y direction changes the direction of the movable table 22 at right angles and moves it in the χ direction.

An arm 27 with a rack (linear tooth shape) is fixed to one end of the slide plate 23, and a bottle 28 is implanted in the protruding tip of the arm 27. On the other hand, in the copying machine main body 1,
A cam member 29 having a grooved cam portion 29A is fixedly installed. The bin 28 fits into this grooved cam portion 29A. The grooved cam member 29A has the same shape as the curve @(T) representing the magnification correction movement amount δ(χ).

Further, a rack (linear tooth type) 30 is fixed to the lower surface of the lens unit table 20, and meshes with a pinion (gear) 31 rotated by a drive source on the copying machine main body 1 side.

A bearing member 32 is provided on the upper surface of the lens unit table 20,
33 is fixed, and a hollow shaft 34 is rotatably supported between both bearing members 32 and 33. A pinion (gear) 35 is fixed to one end of the hollow shaft 34, and the rack 27A of the arm 27 is fixed to the pinion 35.
It fits perfectly.

In the copying machine main body 1, when the variable magnification setting information is input, the pinion 31 is rotated by a rotation amount corresponding to the variable magnification ratio by the driving source, and the lens unit table 20, which is integrated with the rack 30, is rotated by the driving source.
is moved in the optical axis direction (X direction).

The amount of movement at this time corresponds to the magnification proportional movement amount ΔB(χ). When the lens unit table 20 moves by ΔB(χ), the bin 28 of the arm 2, which is integrated with the lens unit table 20, also moves by ΔB(χ).
Although it moves in a direction parallel to the optical axis (X direction), the cam member 29
It is regulated by sliding in the grooved cam portion 29A, and also moves in the Y direction by δ(χ) corresponding to the magnification correction movement amount. bottle 2
When the arm 27 and slide plate 23 move by δ(χ) in the Y direction, the bin 26 fits into the groove 23A with an inclination angle of 45° provided on the slide plate 23, and Since the moving plate 22 moves by δ(χ) in the X direction, the lens 14 moves by δ(χ) in the X direction (optical axis direction).
You will only have to move.

Next, the third mirror unit 17 including the fourth mirror 15 and the fifth mirror 16 is assembled into a machine frame 36, and an eye member 37 is fixed to the side wall of the machine frame 36. The guide member 37 is fitted into a rail member 38 fixed to the copying machine main body 1 and is movable.

A bottle 39 is fixedly installed on the upper surface of the horizontal base portion of the guide member 37. The pin 39 fits into a groove cam portion 40A provided on the slide plate 40 and slides thereon. Groove cam part 40
The inclination angle A is set so that the machine frame 36 moves half the amount of movement of the slide plate 40.

Further, the slide plate 40 is movable in the Y direction along a guide member (not shown) on the -L surface of the horizontal base portion of the machine frame 36.

An arm 41 with a rack 41A (linear tooth profile) is fixed to one end of the slide plate 40. The rack 41A
A pinion 42 having the same pitch circle as the pinion 35 meshes with the pinion 42 . A shaft 43 that rotates without being integrated with the binion 42 is fitted into the inner diameter portion of the hollow shaft 34 and is freely expandable and contractible in the axial direction. Further, the fitting portion between the shaft 43 and the hollow shaft 34 is provided with a square cross section or a key, so that they can rotate together.

Previously, the lens 14 on the lens unit table 20, which had been moved in proportion to the magnification by the rack 30 and the pinion 31, was moved to compensate for the magnification by the cam member 29, but at the same time the arm 27 was moved to compensate for the magnification. The hollow rack 7 is rotated by the meshing of the rack 27A and the pinion 35. As a result, the shaft 43 that fits and locks into the inner diameter portion of the hollow shaft 34 is rotated integrally and also extends and contracts in the axial direction.

As the shaft 43 rotates, the pinion 42 that is integrated therewith moves the arm 41 having the rack 41A and the slide plate 40 in the Y direction. The amount of movement thereof is equal to the amount of movement of the arm 27 and the slide plate 23, and is the magnification correction movement amount δ(χ). By the movement of the slide plate 40, the grooved cam member 40A moves the bin 39 and the machine frame 36 integral therewith in the X direction along the rail member 38, and the amount of movement is equal to the amount of magnification correction movement δ(χ). It is 172.

As described above, the variable magnification device of the present invention is rotationally driven by the drive source in response to the input of variable copying information, and the lens 14 is driven by the proportional variable magnification movement amount ΔB(χ) and the variable magnification correction movement amount δ. (χ)
By moving the third mirror unit 17 by 172·δ(χ) in the optical axis direction by the combined amount of movement, the image is copied onto the imaging surface of the photosensitive material S at a predetermined variable magnification. can be caused to form.

Although the driving force transmission means explained in the above embodiments used a crane and a pinion, wires and pulleys, toothed pulleys and toothed belts, etc. may also be used to achieve the required amount of displacement. It is also possible.

〔Effect of the invention〕

As described above, according to the variable magnification device for a copying machine of the present invention, it is possible to perform continuous zoom magnification by connecting and driving with a simple mechanism without requiring a complicated electronic control circuit or drive mechanism. It has the advantage of being less likely to cause trouble and can be manufactured at a low cost.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a part of a magnification variable device for a copying machine according to the present invention, and FIG. 2 is a sectional view of the magnification variable device. FIG. 3 is a block diagram of the variable magnification optical system, and FIG. 4 is a diagram illustrating the optical path length of the variable magnification optical system. FIG. 5 is a diagram illustrating the amount of lens movement by the variable magnification device according to the present invention. 1...Copy machine body 14...Lens 15...
・4th Mira-1
6... Meat) 5 Mirror -17... Second mirror unit

Claims (1)

[Claims] In a variable magnification device, a scanning optical system for image exposure is constituted by an exposure light source, a movable optical path conversion mirror and a lens, and the copying magnification is changed by moving the optical path conversion mirror and lens along an optical axis. , a first moving means for moving the lens in the optical axis direction in proportion to the copying magnification;
a second moving means for correcting the lens position in response to the second moving means; and a third moving means for moving the position of the optical path conversion mirror in response to the second moving means; The moving means is rotated by being engaged with a first rack provided on a moving member of the second moving means, a second rack provided on a member for moving the optical path conversion mirror, and the first rack. A lens and a mirror in a variable magnification device comprising a first pinion shaft and a second pinion shaft that transmits the rotation of the first pinion shaft and is relatively movable in the axial direction to move the second rack. interlocking device.