JPS6118978A - Color deviation adjusting device of two-color copying machine - Google Patents

Abstract

PURPOSE:To correct color deviation by splitting luminous flux into two through a luminous flux splitting means, providing a longitudinal and a lateral color deviation adjusting mechanism to a mirror behind it, and forming a latent image on individual photosensitive body surfaces and performing development, transfer, and fixation. CONSTITUTION:Longitudinal color deviation is adjusted by rotating a mirror 5 as shown by an arrow around a straight line L1 which runs on the intersection P of the optical axis 15 of luminous flux incident on the mirror 5 and the reflecting surface of the mirror 5 and crosses an optical axis 15 in the mirror plane at right angles. Further, lateral color deviation is adjusted by rotating the mirror as shown by an arrow B around a straight line L2 which runs on the point P and is contained in the mirror plane and nearly equal to a straight line crossing the straight line L1 at right angles. Further, a magnification deviation adjustment is made by moving the mirror 5 in parallel to the incident light optical axis 15 as shown by an arrow A. The mirror 5 equipped with those mechanisms is provided behind luminous flux split into two by the luminous flux splitting means and latent images are formed on individual unshown photosensitive drums with two pieces of luminous flux, and developed, transferred, and fixed, thereby easily adjusting color deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a color shift adjustment device for a two-color copying machine that utilizes luminous flux division.

In a conventional two-color copying machine, for example, as shown in FIG. 5, a beam splitting means 2 such as a half mirror is arranged on the output side of an imaging lens 1 of an exposure optical system, and the beam splitting means 2, such as a half mirror, is used to divide the reflected beam of the original into a fixed proportion. The light is divided into a reflected light beam and a transmitted light beam, and each of the divided light beams is reflected by a mirror to form an image on the photoreceptor drums 8 and 9J on each side at a predetermined exposure position of 6°7. The latent images corresponding to the respective color images formed in the process are developed with toners of different colors, and the resulting toner images are sequentially transferred onto the photoreceptor drum 9.8 at transfer positions 11 and 10. A copying machine that creates a copy of a two-color image having the same positional relationship as the two-color image of the original by superimposing the image on a transfer paper 12'' that is conveyed at the same circumferential speed as the drum. It has been known. In order to form a reverse image on each photoreceptor 9, 8, the number of mirrors arranged between the document surface and the photoreceptor surface needs to be an even number, so the optical path of the light beam transmitted by the half mirror 2 is The number of mirrors provided in the beam and the number of mirrors provided in the reflected light beam are either an odd number or an even number. In the example shown in FIG. 4, one mirror 5 is inserted in the optical path followed by the transmitted light beam, and two mirrors 3.4 are provided in the optical path followed by the reflected light beam.

Copying with this type of two-color copying machine" In order for the two-color images to be in the same positional relationship as on the original, one is to optically transfer the projected images onto the two photoreceptors. It is necessary that the projections match in position. That is, in FIG. 5, the creepage distance from the exposure position 6 of the photoreceptor drum 8 to the transfer position 10 is S1, the creepage distance from the exposure position 7' of the photoreceptor drum 9 to the transfer position 11 is S3, and the creepage distance of both photoreceptor drums is S1. When the distance between the transfer positions 11 and 10 is 82,
The requirement is that S+=82+83.

Also, when viewed three-dimensionally, as shown in Figure 6, two photoreceptor drums 8, 9 J: of line segments of two colors that are completely parallel, have the same length, and have both end positions aligned on the original. It is only necessary that the relative positions of images q and r are correct. That is, it is only necessary that the relative position of the end face Q1 of the two line segments q and r with respect to R8 and the relative position of Q2 with respect to R2 are correct. Since a point on a plane has two degrees of freedom, it is sufficient to have four degrees of freedom to determine the relative positions of two line segments. That is, the adjustment parameter after lens 1 may be set to 4. If you think about it another way, you may think that it is sufficient to match the following four color shift parameters.

For example, if the black line segment q and the red line molecule 6 shown in FIG. Due to the difference in refractive index caused by the difference in refractive index, a shift occurs between the two color images on the transfer paper. This is called "color shift." Figure 7 (b), (C), (d) for color shift.

There are four modes shown in (e). Each figure shows the position of the red line molecule based on the black line segment q, and its correct position r.
. Shown in comparison with (b) As shown in the figure, the state in which the line molecules are shifted in the scanning direction is called "vertical shift." Furthermore, as shown in Figure (c), the state of deviation in the direction perpendicular to the scanning direction is called "lateral deviation." Also, when the image is oblique to the original image, it is called "skew deviation". In addition, a state where the image is expanded or contracted more than the original length is called 1 magnification shift.

In order to completely match both color images to the same state as the original in a two-color copying machine using an overlapping transfer method, it is necessary to match the deviations of the four modes described above. Normally, when performing two-color copying, the color shift is 0.2 degrees or less, preferably 0.2 degrees or less.
It is desirable to set it to 1■ or less; if it is more than that, color shift becomes noticeable and the copy becomes unsightly.

Now, to explain a conventional general color misregistration adjustment method using the apparatus shown in FIG. The magnification shift, horizontal shift, and vertical shift are adjusted using the image projected onto the image as a reference. However, as described above, it is necessary to adjust four parameters in order to completely adjust the color shift. However, the degrees of freedom in the plane are 3
Therefore, only three parameters can be adjusted by simply displacing the mirror 5.

To explain in more detail, when adjusting the horizontal misalignment by dl, ■, as shown in FIG. If the second line molecule image on the photoreceptor 9 is moved to the back side of the position shown by the solid line as shown in FIG. However, as shown in FIG. 8, the light beam reflected on the near side of the mirror 5 is projected to the left of the original projection position, and on the back side it is projected to the right, so the image is not as shown in FIG. The image is rotated by a certain angle, causing skew deviation. From this, it will be understood that the horizontal deviation and the skew deviation are related to each other. Therefore, if you adjust the lateral deviation by displacing one mirror other than mirror 5, and cancel out the skew deviation by adjusting the lateral deviation between mirror 5 and the other mirror, all color deviations can be eliminated. Can be adjusted.

Now, for example, when adjusting the vertical color shift, horizontal color shift, and magnification shift using the mirror 5, the vertical color shift adjustment is performed using the mirror 5.
is rotated around a straight line extending in the longitudinal direction of the slit (longitudinal direction of the mirror 5), and the incident position 7 on the photoreceptor drum 9 in FIG. 5 is shifted in the circumferential direction of the photoreceptor drum.

Further, to adjust the horizontal color shift, rotate the mirror 5 around a straight line extending in the lateral direction of the slit (the lateral direction of the mirror 5), and adjust the incident position on the photosensitive drum 9''. The magnification shift can be adjusted by moving the mirror 5 in the optical axis direction (C), and by adjusting the vertical color shift caused by this movement.

Now, the rotation center of the mirror 5 for the above-mentioned vertical color shift adjustment and complementary color shift adjustment is set as shown in FIGS. 10 and 11 from the viewpoint of simplifying the configuration. I often took the 14 in a place away from the mirror 5. In this case, since the intersection between the incident optical axis 15 and the reflective surface of the mirror 5 moves, the optical path length from the lens to the incident position on the photoreceptor drum changes, resulting in vertical color shift and
Adjustment of the complementary color shift actually causes a magnification shift, which needs to be adjusted, and it becomes necessary to perform the vertical color shift adjustment again as the magnification shift is adjusted, which has the disadvantage of forcing trial and error adjustment. .

Purpose The present invention eliminates the above-mentioned drawbacks of the conventional color shift adjustment device for a two-color copying machine having a light beam splitting means and two photoreceptors, and provides vertical color shift adjustment and complementary color shift adjustment that do not affect magnification shift. It is an object of the present invention to provide a color misregistration adjustment device for a two-color copying machine having the above-described configuration, which allows easy color misregistration adjustment without causing any damage, and can also omit a magnification adjustment mechanism in some cases.

Structure: In order to achieve the above object, the present invention provides a single mirror behind the light beam splitting means with a bias color shift adjustment mechanism and a complementary color shift adjustment mechanism, and the bias color shift adjustment mechanism adjusts the amount of light incident on the mirror. The mirror is configured to be able to be rotated around a straight line that passes through the intersection point P between the optical axis and the mirror's nonconforming surface and is included in the mirror surface and perpendicular to the optical axis as the rotation axis, and the horizontal color shift adjustment mechanism is passing through the intersection P and being included in the mirror surface;
A straight line L that is approximately equal to the straight line perpendicular to the straight line L,
The mirror is configured such that the mirror can be rotated and adjusted using 2 as a rotation axis.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a diagram schematically showing how to displace the mirror for adjusting color shift according to the present invention. The horizontal color shift adjustment is performed by rotating the straight line L1 included in the mirror surface and orthogonal to the optical axis 15 as the rotation axis as shown by the arrow C. The adjustment is performed by rotating the straight line L2, which is included and perpendicular to the straight line L1, as a rotation axis as shown by the arrow B, and the straight line L2 is equal to V. moreover,
If it is necessary to adjust the magnification shift, the mirror 5 is moved parallel to the incident optical axis 15 as shown by arrow A to make the adjustment.

FIGS. 2, 3, and 4 show the construction of an embodiment of an apparatus in which the mirror is movably supported as described above and is displaced to adjust color misregistration.

The color shift adjustment device 300 includes a magnification adjustment member 310 that is movable parallel to the optical axis 15 with respect to the copying machine frame 16, a support plate 306 fixed to the magnification adjustment member 310, and a magnification adjustment member 310 that is movable in parallel to the optical axis 15 with respect to the copy machine frame 16, and a support plate 306 that is movable around the straight line L2 with respect to the support plate 306. A horizontal color shift adjustment plate (second adjustment plate) 305 is rotatably supported on the horizontal color shift adjustment plate 305, and a shaft is supported rotatably around the straight line L at one longitudinal end of the horizontal color shift adjustment plate 305. a color shift adjustment plate (first adjustment plate) 303 that integrally holds one end of the mirror 5 in the longitudinal direction;
A vertical color shift adjustment knob 308 that rotates and adjusts the vertical color shift adjustment plate 303 around the axis L1, and a horizontal color shift adjustment plate 30.
5 around the axis L2 with respect to the support plate 306, and a magnification adjustment knob 313 that displaces the magnification adjustment member 310 in parallel to the optical axis 16 with respect to the machine frame 16. ing.

The mirror 5 has a mirror surface at two points on both sides of the straight line L1 at the end on the near side in FIG. 303b by a pressing spring 302a, and at one point on the straight line L1 at the opposite end, the mirror surface is pressed against the projection 305a of the horizontal color shift adjustment plate 305 by a pressing spring 302b.

The vertical color shift adjusting plate 303 is pivotally supported by the rotary shaft 304 provided on the straight line L1 with respect to the loss color shift adjusting plate 305, and the vertical color shift adjusting plate 303 and the vertical color shift adjusting plate 303 are connected to each other by sandwiching the straight line. Compression spring 31 provided between displacement adjustment plate 303
5 and the vertical color shift adjustment knob 308, the mirror 5 can be rotated around the straight line L1, and thereby the mirror 5 can also be rotated around the straight line L1 to adjust the vertical color shift.

The horizontal color shift adjustment plate 305 has a straight line L2 both above and below the center part.
It is supported by the support plate 306 by rotating shafts 807a and 307b provided at the second side, and in FIG. A knob 309 is provided. Therefore, the horizontal color shift adjustment knob 309 rotates the horizontal color shift adjustment plate 305 around the straight line L2, and the mirror 5 held thereon via the vertical color shift adjustment plate 303 is rotated around the straight line L2. You can adjust the color shift.

The magnification adjustment member 310 has two long holes a as shown in FIG.
ioa and atob, through which guide bins 811a and 3111) are implanted in the machine frame 16, and compression springs 812a and 812b provided between the enlarged head and the magnification adjustment member 310 operate the machine. It can slide parallel to the optical axis 15 while being pressed against the frame 16. In FIG. 2, the right end of the magnification adjustment member 310 and a member 314 fixed to the machine frame opposite to that end are provided with screws cut in opposite directions on both sides of the axis of the magnification adjustment knob 313. are screwed together. Therefore, by turning the magnification adjustment recess 8Ll, the magnification adjustment member 310 can be moved along with the mirror 5 held therein in the direction of the optical axis 15 to adjust the magnification.

In the above color shift adjustment device, when adjusting horizontal color shift and vertical color shift, the mirror is rotated about a straight line passing through the intersection point P between the optical axis of the incident light beam and the mirror surface, so the optical path length is It does not change and does not affect the magnification shift. Therefore, if the accuracy of the mirror rotation center position for adjustment is made sufficiently high, magnification adjustment can be omitted.

The vertical color shift adjustment plate 303, the horizontal color shift adjustment plate 805, and the support plate 306 that integrally support the mirror of the above embodiment constitute a so-called gimbal mechanism (double suspension ring support mechanism), and thereby the mirror 5 The position of one point P on the top is held constant and can be tilted in any direction.

In this type of support method, the support object (mirror 5 in this example) is generally supported at both ends by pins (304) whose axis coincides with the straight line L1, so it is difficult to adjust the vertical color shift. The plate 80B needs to be provided on both sides of the mirror 5 or formed as an annular member surrounding the entire circumference of the mirror, which has the drawback of increasing the number of parts and increasing the space required.

In this embodiment, as a mechanism for making the mirror 5 freely rotatable around the straight line L1, one end of the mirror 5 in the longitudinal direction (direction of the straight line L1) is vertically aligned at two points on both sides of the straight line L1. Two points 808a on the adjustment plate 303.

803bK is pressed by a spring and supported integrally, the other end is straight, and one point on the top is pressed by a spring to a point 305a on the horizontal color shift adjustment plate 305, so that it can freely rotate around the point 805a. Since the adjustment device is supported in a configuration in which the adjustment device is supported, the number of parts is reduced, and the space occupied by the adjustment device is also reduced.

Effects As described above, according to the present invention, the vertical color shift adjustment and the horizontal color shift adjustment do not affect the magnification shift, so after adjusting the magnification shift first, the vertical color shift adjustment and the horizontal color shift adjustment are performed. If the horizontal color shift adjustment is performed, the color shift can be easily adjusted, and the number of steps required for adjustment is significantly reduced compared to the conventional method. Also, if you ensure the accuracy of the rotation center position of the mirror for adjustment,
It is also possible to omit the magnification shift adjustment.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram explaining the principle of the color misregistration adjusting device according to the present invention, FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention, and FIG.
The figure is a top view seen in the direction of arrow 111-N in Figure 2, Figure 4 is a perspective view showing both ends in the longitudinal direction, and Figures 5 to 9 explain the concept of color misregistration in a two-color copying machine. Schematic diagram for
FIGS. 10 and 11 are perspective views showing an example of a conventional color shift adjustment method. 1... Imaging lens 2... Light beam splitting means 5...
・Mirrors 8, 9...Photosensitive drum 300・
...Color shift adjustment devices 802a, 802b...Mirror pressing spring 803...
Vertical color shift adjustment plate (first adjustment plate) aoaa, 808b
...Mirror support point 305...Horizontal color shift adjustment plate (second adjustment plate) 305a...Mirror support point 306...Support plate

Claims (3)

[Claims] (1) After the slit-shaped light beam reflected from the original passes through the imaging lens, the light beam splitting means divides it into a transmitted light beam and a reflected light beam at a fixed ratio, and each of the divided light beams is focused on a separate photoreceptor surface. In a color shift adjustment device for a two-color copying machine, which develops latent images corresponding to each color image formed on the surface of a photoreceptor in a predetermined process with toner of different colors, and transfers them onto the same transfer paper in an overlapping manner. , a vertical color shift adjustment mechanism and a horizontal color shift adjustment mechanism are provided for one mirror located behind the light beam splitting means, and the vertical color shift adjustment mechanism adjusts the angle between the optical axis of incidence on the mirror and the reflection of the mirror. The mirror is configured to be rotatably adjustable with a straight line L_1 included in the reflecting surface and perpendicular to the optical axis passing through the intersection point P with the surface, and the horizontal color shift adjustment mechanism passing through the point P and being perpendicular to the optical axis. A straight line L that is included in the reflective surface of the mirror and is approximately equal to the straight line that is perpendicular to the straight line L_1.
A color shift adjustment device characterized in that the mirror is configured to be rotatable with _2 as a rotation axis. (2) A mechanism that allows the mirror to rotate around the straight lines L_1 and L_2 passing through point P and intersecting each other at right angles includes a first adjustment plate that integrally holds the mirror; a second adjustment plate rotatably supported around the straight line L_1; a support that supports the second adjustment plate rotatably around the straight line L_2 and fixed at a predetermined position of the copying machine frame; The color shift adjustment device according to claim 1, further comprising a plate. (3) The above-mentioned mirror is supported by a spring on the first adjustment plate at two points on both sides of the above-mentioned straight line L_1 at one end in a direction parallel to the straight line L_1, and at the other end on the straight line L_1. 3. The color misregistration adjusting device according to claim 2, wherein one point is supported by the second adjusting plate under pressure by a spring.