JP3318134B2 - Color image forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus, and more particularly, to a driving mechanism for driving a plurality of photosensitive members provided in an electrophotographic color image apparatus using a plurality of photosensitive members. The present invention is particularly suitable for use in a rotation transmission mechanism of a device having a plurality of rollers or shafts rotating at a constant speed.

[0002]

2. Description of the Related Art An electrophotographic recording apparatus irradiates a drum-shaped photosensitive member having a negatively charged photoconductor layer with a light modulation signal according to an image density, for example. An electrostatic latent image corresponding to the image is formed thereon, toner is electrostatically adhered to the electrostatic latent image, a developing process is performed to visualize the electrostatic latent image on recording paper, and a heat treatment is performed on the latent image to fix it. Is a recording device for recording an image.

A color image forming apparatus based on the electrophotographic method disperses the light modulation signal into monochromatic light of three primary colors, and Y (yellow), M (Y) provided corresponding to the monochromatic light obtained by the spectroscopy. Using the photoconductors for magenta), C (cyan), and K (black) provided as necessary, the above-described electrophotographic recording is sequentially superimposed and developed on one sheet of recording paper. Is fixed to form a color image.

In order to obtain a color image without color misregistration,
It is necessary to rotate the photosensitive member synchronously so that the rotational speed of the photoreceptor for each monochromatic light is kept correctly and constant with respect to the moving speed of the recording paper. For this reason, in an electrophotographic color image forming apparatus, four photoconductors for Y, M, C and K are arranged in a line, and each photoconductor is driven by a motor. Attempts have been made to rotate at the same rotational speed using a belt or a worm mechanism or the like.

[0005] As a known document relating to a rotation mechanism of a photoconductor for rotating a plurality of photoconductors at the same rotation speed,
Japanese Utility Model Application Laid-Open No. 2-95344, "Photosensitive Element Driving Device in Color Image Forming Apparatus", Japanese Utility Model Application Laid-Open No. 2-95345, "Color Image Forming Apparatus", Japanese Patent Application Laid-Open No. 2-129666, "Color Printer"
And Japanese Patent Application Laid-Open No. 2-157868 “Color recording device”.

In the photoconductor driving device disclosed in Japanese Utility Model Laid-Open No. 2-95344, a worm wheel is mounted on the photoconductor shaft of each of four photoconductors (drum-shaped) provided for each single color, and each worm is provided with a worm wheel. A mechanism for simultaneously driving four photoconductors by driving a single worm shaft having a series of worms engaged with a wheel, and transmitting rotation while maintaining a constant distance between the worm and the worm wheel. It is.

In the photoconductor driving device disclosed in Japanese Utility Model Laid-Open No. 2-59345, a worm wheel mounted on each photoconductor shaft is mounted on one worm shaft, similarly to the Japanese Utility Model Application Laid-Open No. 2-95344. And a mechanism driven simultaneously by a series of worms.

In the photoconductor driving device disclosed in Japanese Patent Application Laid-Open No. 2-129666, a drive motor is disposed in the center, and two photoconductors disposed on the left and right sides as viewed from the drive motor are provided with an endless belt-shaped belt and a gear. , The driving error is reduced by accumulating the rotation errors by driving the two motors simultaneously.

In the photoconductor driving device disclosed in Japanese Patent Application Laid-Open No. 2-157868, a driving motor is installed at a position closest to a photoconductor disposed in the middle, and two photoconductors on the left and right sides of the driving motor are connected to a belt. The rotation of the drive motor is transmitted using a pulley or a gear, and the rotation transmission mechanism is small and does not accumulate rotation errors.

[0010]

However, the above-described conventional rotation transmission mechanism has the following problems. (1) Each of the actually-opened Japanese Patent Application Laid-Open Nos. 2-95344 and 2-95345 relates to a method of driving by a combination of four worms and a worm wheel.
In this configuration, the accuracy of the components, for example, the accuracy of the tooth profile of the worm and the worm wheel, particularly the runout causes a rotation error. In particular, the fourth photoconductor at the position farthest from the drive motor rotates due to accumulation of rotation errors. Further, there is a disadvantage in that if the precision of the parts is improved to reduce the rotation error, the cost is increased, the mounting member of the photoconductor is complicated, and the apparatus cost is increased. (2) Since the belts and gears are used in the Japanese Utility Model Laid-Open No. 2-129666, high precision parts are required as in the case of the above (1), and the equipment cost is high. If, for example, a timing belt is used as the belt, a meshing error between the timing belt and the belt pulley occurs, or the belt vibrates, so that it is difficult to transmit good rotation. (3) Japanese Patent Application Laid-Open No. 2-157868 is similar to the above (2), but also has a drawback that vibration generated by a belt or a gear is transmitted as it is. In particular, in the case of belt transmission, rotation is transmitted by one stage from the drive motor, one stage further from the driven pulley via each pulley, and three stages of pulleys from the driven pulley to the pulley of the photoconductor. I have. According to this rotation transmission mechanism, the vibration generated between each pulley and the belt becomes extremely large and is accumulated, so that the rotation transmission accuracy is deteriorated.

The present invention has been made in view of the above-mentioned circumstances, and in particular, a plurality of photosensitive members (generally four drums in a color recording apparatus) are provided with a vibration source by minimizing gears, pulleys, and the like. It is an object of the present invention to provide a color image forming apparatus having a simple and inexpensive driving device which is driven to rotate accurately with reduced noise.

[0012]

According to the present invention, in order to solve the above-mentioned problems, (1) a plurality of photoconductors arranged in a straight line and a recording sheet is linearly conveyed along the photoconductors. In an image forming apparatus having a conveying unit, which visualizes an electrostatic latent image formed on the photoconductor when the recording paper passes through the photoconductor and transfers the latent image to the recording paper, the image forming apparatus is disposed adjacent to the recording paper. The photoreceptor is rotatably supported by a plurality of linked link mechanisms, and (2)
In the above (1), the plurality of linked mechanisms are arranged side by side by arranging a plurality of two links having cross-connecting portions rotatably cross-connected to each other, and rotating the opposing free ends of each of the links. A plurality of free end connecting portions are movably connected to each other, and the lengths of opposing sides of a quadrilateral formed by the obtained links are equalized.
(3) In the above (1) or (2), one of the left and right ends of the free end connecting portions of the link mechanisms arranged in a line is rotatably supported by the apparatus main body side, and the other free end connection is established. The part is rotatably attached to a support member supported on the photoreceptor shaft. (4) In the above (1) or (2), the free of the link mechanisms arranged in a line. One end at the center of the end connecting portion is rotatably supported on the apparatus main body side, and another free end connecting portion is rotatably attached to a support member supported on the photoconductor shaft.
(5) In the above (1) or (2), one of the left and right ends of the cross connection portions of the link mechanisms arranged in a row is rotatably supported by the apparatus body, and the other cross connection portion is (6) In the above (1) or (2), the cross-connecting portions of the link mechanisms arranged in a line in the above (1) or (2). (7) the center portion of is rotatably supported by the apparatus main body, and another cross-connecting portion is rotatably attached to a support member supported on the photoreceptor shaft. 1)
In any one of (6) to (6), a follower for transmitting power from a drive motor to any one of the plurality of photoconductors connected to the link mechanism via the support member. Are fixed.

[0013]

According to the present invention, a plurality of two links each having an intersecting portion in which two intersecting crossing portions are rotatably connected are arranged side by side, and the intersecting portions are arranged in a line. ,
A link mechanism having a plurality of equilateral quadrilaterals arranged side by side with the free end connection portion and the cross connection portion, the free end of the adjacent link being a free end connection portion rotatably connected; One of the left and right ends or the central part of the free end connecting part (or cross connecting part) of the mechanism is a fixed part that is rotatably fixed, and one of a plurality of other free end connecting parts (or cross connecting parts). Is rotated, the other free end connecting portions (or cross connecting portions) rotate at the same phase (or 180 ° phase difference) and the same rotation speed in conjunction with this rotation while maintaining the same interval. By utilizing this, a plurality of photoconductors are driven synchronously at the same rotational speed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. First, a color image forming apparatus to which the present invention is applied will be described.

FIG. 24 is a view for explaining an example of a color image forming apparatus to which the present invention is applied.
Is a scanner unit, 22 is an image processing unit, 23 is a printer unit,
24 is a document table, 25 is a lamp, 26 is a mirror, 26 is an imaging lens, 29 is a dichroic prism, 31 is a light receiver, 32 is a laser beam device, 33 is a recording device, 34 is a photoconductor, 35 is a charging charger, 36 is a developing device, 37 is a transfer charger, 38 is a paper feed roller, 39
Is a paper feeding unit, 40 is a registration roller, 41 is a transfer belt,
Reference numeral 42 denotes a fixing roller, 43 denotes a paper feed roller, and 44 denotes a photoreceptor shaft. The color image forming apparatus includes a scanner unit 21, an image processing unit 22, and a printer unit 23. The subscripts Y, M, C, K, R, B, and G are yellow, magenta, cyan, black, red,
Blue and green.

The scanner section 21 scans and illuminates the original on the original placing table 24 with a lamp 25 such as a fluorescent lamp, and reflects the reflected light from the original through mirrors 26, 27 and 28 and an imaging lens 29 to form a dichroic prism 30. And the image-forming light is split into, for example, red (R), green (G), and blue (B) wavelength light.
The light enters the CD 31 R, the CCD 31 G, and the CCD 31 B and is transmitted to the image processing unit as an analog light signal for each wavelength.
The image processing unit 22 converts the analog optical signal into a digital signal, performs necessary processing, and performs recording color information for each color.
Y (yellow), M (magenta), C (cyan), K
The (black) signal is output and sent to the laser light emitting devices 32Y, 32M, 32C, and 32K of the printer unit 23.

In the printer section 23, the laser light output device 3
2. Recording apparatuses 33Y, 33M, 33C, 33K having the same configuration for recording in colors according to the color information emitted from
Are arranged at equal intervals. Now, the recording device 33C will be described with the recording device as a representative. Recording device 3
3C is a photosensitive member 34C uniformly charged by a charging charger 35C, similarly to a known electrophotographic copying apparatus.
Is irradiated with laser light from a laser light emitting device 32C to form a latent image of a cyan light image. The latent image is formed as a visible cyan image on a photoreceptor 34C by a developing device 36C. The visible image is transferred onto the recording paper by the transfer charger 37C.

The recording paper is fed from a paper feeding section 39 by a paper feed roller 38, the leading ends thereof are aligned by a registration roller 40, and is conveyed to a transfer belt 41 at the same timing. The recording papers 33K, 33C and 33M are sequentially arranged. , 33Y, the image is transferred to the recording paper in a color-matched manner, is fixed by the fixing roller 42, and is discharged by the discharge roller 43. At this time, the recording paper is transferred to the transfer belt 4 electrostatically attracted to the transfer belt 41.
It is transported at a constant speed equal to the speed of 1.

The photoconductors 34K, 34C, 34M and 34Y are rotated without causing slippage with respect to the transfer belt 41. Since the outer diameters of the photoconductors 34K, 34C, 34M, and 34Y are equal, the photoconductor shafts 44K, 44C, 44M, and 44Y are rotated at a constant speed.

[Embodiment 1] FIGS. 1 to 5 are views for explaining Embodiment 1 of a link mechanism for synchronously driving a photosensitive member in a color image forming apparatus according to the present invention.
In the figure, A ₁ , A ₂ ... Are long links A (hereinafter referred to as links A), B ₁ , B ₂ ... Are short links B (hereinafter referred to as links B), and P ₁ , P ₂ . Part (node), Q ₁ ,
_{Q 2 ..., R 1, R} 2 ... free end connecting _{portion, S 1, S 2, ...} , S 4
Is a rotating circle of each free end connecting portion, 1, 2, 3, and 4 are photosensitive members, and 5, 6, 7, and 8 are driven connecting members.

FIG. 1 is a view for explaining a basic link mechanism of the first embodiment. In the link mechanism shown in FIG. 1, two links A each having the same length L are used.
₁ , A ₂ , and link B are two links B ₁ , B ₂ having the same length (１ ／) L, respectively. Link A ₁ and link B ₁ are:
Middle of link and the link B one end with rotatably crossed linked cross coupling portion P ₁ of the _first A ₁ is constituted.
Similarly, the one free end of the link A ₂ and the link B ₂ is constituted is rotatably crossed linked cross coupling portion P _2, further links B ₁ and the other end portion of the B ₂ Is the free end connecting part Q
₂ , one end of the links A ₁ and A ₂ is connected to the free end connecting portion R ₁
To form a quadrilateral P ₁ Q ₂ P ₂ R ₁ . In FIG. 1, since the lengths (L / 2) of the sides of the quadrilateral P ₁ Q ₂ P ₂ R ₁ are equal, when the free end connecting portion R ₁ has a right angle, it becomes a square and the free ends Q ₁ , Q ₂ , Q ₃ are arranged at equal intervals on the same straight line.

FIG. 2 is a diagram for explaining the operation of the link mechanism shown in FIG. 1, the free end of the link A ₂ (right end)
Q ₃ are is rotatably fixed position (referred to hereafter as fixed point). In this state, for example, the free end connecting portion Q ₂ when rotated in the arrow counterclockwise with the rotation circle S ₁ the free end to Q ₁ links A ₁ had a radius of the rotating circle S ₁ (1/2) the rotation circle S circle according to the _two arrows counterclockwise direction is rotated with equal phase angle equal angular velocity.

Therefore, in a color image apparatus, in order to rotationally drive a plurality of photosensitive members arranged linearly, the plurality of photosensitive members are rotatably supported by a link having a plurality of connecting portions. (Corresponding to item 1)), the plurality of photoconductors can be driven at the same phase and at the same rotational speed. At this time, of course, it is necessary to reduce the play between the links constituting all the connecting portions so as not to affect the rotational speed.

FIG. 3 is a view for explaining a link mechanism obtained by arranging a plurality of links in FIG. 1 side by side. Parts having the same functions as those in FIG. 1 are referred to in the same manner as in FIG. Numbered.

The link mechanism shown in FIG. 3 is obtained when the link mechanisms shown in FIG.
It is composed of six long links A and two short links B. Link B ₂ of the link mechanism shown in FIG. 1, FIG. 3
Then, instead of using link B ₂ as it is, link A ₂
And P ₂ in cross-linked length of the link A ₃ is composed of (L / 2) portions, the link B ₂ in FIG. 3 is cross-linked at the center P ₄ of a long link A ₆ on the right end. In this way,
The link mechanism shown in FIG. 3 is composed of two links A ₁ and A ₂ and two links B ₁ and B ₂ shown in FIG. Six links A ₁ ,
_{A 2, ~, A 5,} A 6 and by connecting with two links B _1, B ₂ and each cross connecting portion P ₁ to P ₄ of the link to the central portion A _2, A _3, A _4, four long links a of the a ₅ is used, the result, three equilateral quadrilateral arranged laterally P ₁ Q _{2
P 2 R 1, P 2 Q} 3 P 3 R 2, P 2 Q 4 P 4 R 3 is constructed (corresponding to claim 2).

In the link mechanism shown in FIG. 3, similarly to the link mechanism shown in FIG. 1, the length of the long link A is L and the length of the short link B is (L / 2). The lengths of the sides connected to the center by the cross connection portions P ₂ and P ₃ are equal (L
/ 2) are configured side by side in the horizontal direction,
The triangles Q ₁ P ₁ Q ₂ , Q ₂ P ₂ Q _3, ..., Q ₄ P ₄ Q _{5 form} a congruent isosceles triangle, and the cross-connecting parts P ₁ , P ₂ ,.
₄ are lined up and have the same height and the same base Q ₁ Q ₂ =
Q ₂ Q ₃ = Q is a _{3 Q 4 = Q 4 Q 5} .

[0027] FIG. 4 is a diagram for explaining the operation of the link mechanism shown in FIG. 3, the free end Q ₅ of the link A ₆ of the right end side is fixed point, the other free end connecting portion Q _1, Q ₂ ... Q ₄ is shows the trajectory of each of the links when rotating on every 90 ° rotation circle S ₁ ... S ₄ in the arrow counterclockwise. In addition,
When the free end Q ₁ and the free connection points Q _{2 to} Q ₄ are located farthest from the fixed point Q ₅ , that is, when the rotation angle is 0 °, the link mechanism is a solid line, and when the link mechanism is at another position, a dotted line is a dotted line. Indicated by.

The link mechanism shown in FIG. 4 has free ends Q ₁ ,
When the free connection ends Q ₂ ,..., Q ₄ are in any of the phases of the rotating circles S ₁ ,..., S ₄ , the above-described relationship of the congruent isosceles triangle is maintained, so that the free end Q ₁ , the free connection End Q ₂ , ~, Q ₄
Are rotated at the same phase and the same rotation speed at equal intervals. At this time, the ratio of the sizes of the turning radii r ₁ ,..., R ₄ of the rotating circles S ₁ ,..., S ₄ becomes smaller by (１ ／) in order from the left end Q ₁ toward the right end fixed point Q _5. The turning radius ratio is 4: 3: 2: 1
In a relationship. This relationship holds true as well when the free end to Q ₁ left a fixed point Q ₅ the free end.

FIG. 5 is a view for explaining an example of a drive mechanism for driving the photosensitive member using the link mechanism shown in FIG. 3, in which 1, 1 to 4 are photosensitive members, and 5 to 5 are illustrated. , 8 are support members (in the figure, the specific structure is not shown, and is represented by the length from the rotation axis of the photoconductor to the free end connecting portion).

[0030] In FIG. 5, the photosensitive member 1, -, 4 the rotation axis O _1, O ₂ in the cylindrical body of the same radius, ~, has a O _4,
The rotating shafts O ₁ ,..., O ₄ are rotatably arranged on the same straight line at equal intervals. The free end Q ₅ at one end of the link mechanism shown in FIG. Free end Q ₁ ,
Free connecting end Q _2, ..., and Q _4, the photosensitive member 1, ~, of 4 rotation axis O _1, O _2, ~, between O _4, respectively, the arm-shaped or disk-shaped supporting member 5 , 6,..., 8 (not shown) are rotatably connected (corresponding to claim 3).
By rotating any one of the rotating shafts O ₁ , O ₂ ,..., O ₄ among ₂ , ₃ , and ₄ by a drive motor (not shown), the other three driven photosensitive members have the same phase and the same phase. It is rotated at a rotation speed.

Second Embodiment FIGS. 6 to 10 are views for explaining a link mechanism according to a second embodiment of the present invention, and FIG. 6 illustrates a link mechanism which is the basis of the second embodiment. 7 to 10 show rotation angles 0 to 0 when the free end connecting portion of the link mechanism shown in FIG.
It is a figure for demonstrating the motion of the free end connection part of a link mechanism at the time of rotating every 90 degrees between 270 degrees,
Parts having the same functions as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

As shown in FIG. 6, the link mechanism according to the second embodiment has a center of a free end connecting portion of a link mechanism in which four long links A and four short links B form three equilateral shapes. Is fixed, and the rotation of one free end connecting portion when the other free end connecting portion is rotated is used.
Link A ₁ , A ₂ , A ₃ , A ₄ and four links B ₁ , B ₂ ,..., B _{4 of} length (１ ／) L, and link A ₁
And configure the A ₂ and Link A ₃ and A ₄ and each cross connecting point P _2, which intersect at the center of each other, P _3, further links A ₁ and the link A ₃ and links A ₂ and link A ₄ One free end is rotatably connected by Q ₂ and R ₂ , respectively, and the other free ends of the links A ₁ and A ₂ and the links A ₃ and A ₄ are links B ₁ and B ₂ , respectively.
And B ₂ and Link B _3, B ₄ pivotally connected to the free end connecting portion R ₁ and the, Q ₁ and R _3, Q _3, further other links B _1, B ₂ and B _3, B ₄ Are connected rotatably at P ₁ and P ₄ , so that three equal quadrangles P ₁ R ₁ P ₂ Q ₁ and P are arranged side by side with a length of (L / 2). ₂ R ₂ P ₃
Q ₂ , P ₃ R ₃ P ₄ Q ₃ are configured. For this reason, the line connecting the free end connecting portions Q ₁ , Q ₂ , Q ₃ and R ₁ , R ₂ , R ₃ is a straight line, and similarly the cross connecting portions P ₁ , P ₂ , P ₃ , P ₄ The connected line is also a straight line.

The center cross connection Q ₂ of the odd number of cross connection portions Q ₁ , Q ₂ , Q ₃ aligned on a straight line of the link shown in FIG. 6 is fixed, and for example, one cross connection portion Q ₁ is connected. When rotated in accordance with rotation circle S _1, other cross-linking unit Q ₃ are in phase 180
Are different and are rotated at the same rotation speed with the same rotation direction. This situation will be described with reference to FIGS.

(1) State of Start of Rotation (FIG. 7) The intersections Q ₁ and Q ₃ are both at the same distance from the fixed point Q ₂ and are located at the centers O ₁ and O ₂ of the circles of rotation S ₁ and S _2. Fixed point Q
_{On the} far side from ₂

(2) Rotated by 90 ° (FIG. 8) The cross-connecting portions Q ₁ , Q ₂ , Q ₃ and O ₁ , Q ₂ , O ₂ are all on a straight line, and the side Q ₁ Q ₂ = Q since a ₂ Q _3, with respect to the straight line O _1, Q _2, O _2, to the cross connecting part Q ₁ lower, the cross-connection part Q ₂ is in the upper, cross coupling portion Q _1, Q ₂ are each 1
They are at different positions with a phase difference of 80 °.

[0036] (3) In the state of rotation start shown in 180 ° rotational state (FIG. 9) 7, cross-linking unit Q _1, Q ₃ is with respect to the rotation circle S _1, S _2, both the fixed point Q ₂ , But the cross-links Q ₁ and Q ₂ are 18
0 ° is on the side of the diameter closer to the fixed point Q ₂ is in the state shown from the position in FIG. 9 rotated 180 ° because of the phase difference.

(4) State of Rotation at 270 ° (FIG. 10) From the state where the cross-connecting part Q ₁ shown in FIG. 8 is rotated by 90 °, it is further rotated by 180 ° to obtain a straight line O ₁ Q ₂ O _2.
Hand, cross linking unit Q ₁ is on the upper side, cross linking unit Q ₃ are at different positions 180 ° out of phase with each other on the lower side.

[0038] FIG. 11 is shown in FIG. 6, the center of the intersection connecting portion Q ₂ and fixed to the link mechanism having three equilateral quadrilateral, further, two equilateral quadrilateral equal in the left and right laterally It is a figure for explaining operation of a cross connection part of a link mechanism added so that it may line up.

FIG. 11 is a view for explaining a link mechanism in which a plurality of link mechanisms according to the second embodiment shown in FIG. 6 are arranged in the horizontal direction. The link mechanism shown in FIG. 11 is shown in FIG. Link A with long link A, 4 links, short link B,
While the four links are connected to form three equilateral quadrilaterals, the link mechanism formed by connecting twelve long links A and four short links B provides an odd number of seven equilateral quadrilaterals. There are formed a fixed linkage in the middle of the free end connecting portion Q _2.

As described above, in the link mechanism shown in FIG. 11, the links B ₁ , B ₂ and B of the link mechanism shown in FIG.
_3, B ₄ and provided on left and right ends of the fixed point Q _2, the link A that have been added during which time the left and right portions
_{5, A 6, A 7,} A 8 and links _{A 9, A 10, A 11} , A 12
Is provided. These links A ₅ , A ₆ … A ₁₁ ,
Coupling of A ₁₂ is the same as the link mechanism shown in FIG. 6,
Detailed description is omitted.

As a result, the link mechanism shown in FIG.
Sequentially from the fixed point Q _2, the free end on the left and right sides of the straight line connecting portion _{Q 2, Q 1, Q 4} , Q 5 and _{Q 2, Q 3, Q 6} , Q
₇ and these free-end connecting portions Q ₅ , Q ₄ , Q ₁ , Q ₂ , Q ₃ , Q
_6, the length of seven sides including Q ₇ (L / 2) trapezium Q _{5
P 6 R 5 P 5, Q} 4 P 5 R 4 P 1, Q 1 P 1 R 1 P 2, Q 2 P 2 R 2 P
_{3, Q 3 P 3 R 3} P 4, Q 6 P 4 R 6 P 7, Q 7 P 7 R 7 P 8 are constructed. For this reason, the intervals between adjacent free end connecting portions are equal. That side _{Q 5 Q 4 = Q 4 Q} 1 = Q 1 Q 2 = Q 2 Q 3 = Q 3
The Q ₆ = Q ₆ Q _7.

This means that the intervals between the four free end connecting parts Q ₅ , Q ₁ , Q ₃ , Q ₇ arranged alternately are equal,
If with respect to the fixed point Q ₂ and rotated along the Q ₅ on the left to rotate the circle S _3, if the same, the free end connecting portion to Q ₁ left from the fixed point Q ₂ of the link mechanism shown in FIG. 6 each rotating disk S ₁ on the same phase, unlike the right of the free end connecting portion Q _3, Q ₇ each rotation circle S _2, S ₄ on at 180 ° phase, are rotated at the same rotational speed both. When 3 rotation radius of the rotary circle S ₃ at this time, the radius of the rotating circle S ₁ is 1, the radius of the rotating circle S _2, S ₄ are each 1,3.

FIG. 12 is a view for explaining an example of a drive mechanism for driving the photosensitive member using the link mechanism shown in FIG. 11, and parts having the same functions as those in FIG.
The same reference numerals as in the case of are used.

In the embodiment shown in FIG. 12, similarly to the embodiment shown in FIG. 5, the rotation axes O ₁ , O ₂ , O ₃ , of the cylindrical photosensitive members ₁ , ₂ , ₃ , 4 having the same diameter are provided. O ₄ are sequentially arranged in a straight line, and the fixed point Q ₂ of the link shown in FIG. 11 is rotatably attached to the main body side at the center position of the photoconductors ₂ and 3, and the rotation axes O ₁ , O ₂ , O
_3, O ₄ and the free end connecting portion Q ₅ of the link _{mechanism, Q 1, Q 3, Q} 7
Between the arm-shaped or disk-shaped support members 5, 6,
7, 8 (the specific shape is omitted) and are connected rotatably (corresponding to claim 4).

In the photoconductor driving method described in the first and second embodiments described above, the free end of the free end connecting portion of the link mechanism forming a plurality of equilateral quadrilaterals or the center portion is fixed at a fixed point. The rotation drives the photoconductors arranged linearly at equal intervals. However, in the above-described link mechanism, a plurality of cross-connecting portions also rotate at a constant speed, so that the photoconductors are driven using this rotation. You can also.

Third Embodiment FIGS. 13 to 17 are views for explaining a third embodiment of the link mechanism according to the present invention.
FIG. 13 is a view for explaining a basic link mechanism of the third embodiment. FIGS. 14 to 17 show rotation angles of 0, .about., And 270.degree. FIG. 9 is a view for explaining the movement of the cross-connecting part when rotating between 90 ° every 90 °, in which parts having the same operation as in FIG. 1 are denoted by the same reference numerals as in FIG. It is.

The link mechanism shown in FIG.
Link A of the present, consists of a four link B of length (L / 2), rotatable cross connection portion P ₂ intersect at the center constitute the link A ₁ and A _2. Further, at one free end of the links A ₁ and A ₂ , one free end of the links B ₁ and B ₂ , and at the other free end of the links A ₁ and A ₂ , one free end of the links B ₃ and B _4. And rotatably connected with the free end connecting portion R ₁ ,
Q ₁ and R ₂ , Q ₂ are formed, and the other free ends of the links B ₁ , B ₂ and B ₃ , B ₄ are rotatably connected at cross connection portions P ₁ , P ₃ , and two equal equilaterals Quadrilateral P ₁ R ₁ P ₂ Q ₁ ;
P ₂ R ₂ P ₃ Q ₂ is formed.

[0048] In FIG. 13, for example, one of the cross-connection part P ₃ is fixed, when the other intersection connecting portion P ₁ along the rotational circle S ₁ in the arrow counterclockwise rotated, the center of the cross-connection part P _Two
Are rotated in the same phase and at the same rotation speed. Hereinafter, the details of this exercise will be described with reference to FIGS.

(1) State of start of rotation (FIG. 14) The cross-connecting parts P ₁ , P ₂ , P ₃ are on the same straight line, and the rotating circle has centers O ₁ , O ₂ on the straight lines P ₁ , P _3. The cross-connecting portions P ₁ and P ₂ are placed on a straight line far from the cross-connecting portion P ₃ of S ₁ and S ₂ , and from this position, rotation starts in the counterclockwise direction indicated by the arrow. Since the length P ₁ P ₂ = P ₂ P ₃ , the radius of the rotation S ₁ is twice the radius of the rotation S ₂ .

(2) State rotated 90 ° (FIG. 15) Since the length P ₃ O ₁ = 2P ₃ O ₂ and the radius O ₁ P ₁ = 2O ₂ P ₂ , the straight line P ₃ P ₂ P ₁ is also obtained. It is on a straight line and the intersection P ₁
Is rotated by 90 °, the cross connection part P ₂ also rotates by 90 °.

(3) 180 ° rotated state (FIG. 16) Lines O ₁ and O connecting the line P ₁ P ₂ P ₃ connecting the cross-connecting parts, the fixed point P ₃ and the centers O ₁ and O ₂ of the rotating circles. _2, matching in a state intersection connecting portion P _1, P ₂ rotate together 180 ° and P _3.

(4) State of Rotation by 270 ° (FIG. 17) As in the state of rotation by 90 ° shown in FIG. 15, the line P ₁ P ₂ P ₃ connecting the cross-connecting portions is a straight line. cross connecting portion P ₂ when the part P ₁ has rotated 270 ° be 270 ° rotated.

FIG. 18 is a view for explaining a link mechanism according to the third embodiment in which the link mechanisms shown in FIG. 13 are arranged side by side. The link mechanism having two equilateral quadrangles shown in FIG. On the other hand, it has a link mechanism having four equilateral quadrilaterals, with six long links A and four short links B.

The long link A has six links of equal length L, the links A ₁ , A ₂ , A _{3 to} A ₆ , and the short link B has four links of equal length (L / 2). B ₁ , B ₂ ,
, B ₄ , links A ₁ and A ₂ are rotatable at intersection connecting portion P ₂ , links A ₃ and A ₄ are rotatable at cross connecting portion P ₃ , and links A ₅ and A ₆ are rotatable at cross connecting portion P _4. And the free ends of the cross-linked links A ₁ , A ₂ ,..., A ₆ are rotatably connected by free end connecting portions R ₂ , Q ₂ , R ₃ , Q ₃ , respectively. _One free end of B ₁ , B ₂ is a link A ₁ , A ₂ and a free end connection part R ₁ , Q ₁ , and _one free end of the link B ₃ , B ₄ is free connection with a link A ₆ , A _5. It is connected rotatably at the ends R ₄ and Q ₄ ,
The other free ends of the links B ₁ , B ₂ and B ₃ , B ₄ are rotatably connected at cross connection portions P ₁ and P ₅ . As a result,
Four equilateral quadrilaterals P ₁ R _{1 with} side lengths equal to (L / 2)
_{P 2 Q 1, P 2 R} 2 P 3 Q 2, P 3 R 3 P 4 Q 3, P 4 R 4 P 5 Q 4 is formed are arranged laterally.

Therefore, the line connecting the cross-connecting parts P ₁ , P ₂ ,..., P ₅ is a straight line, and the partial straight line P ₁ P ₂ = P ₂ P ₃ =
P ₃ P ₄ = is a P ₄ P _5. Therefore left or right end of the cross connecting portion P ₁ or P ₅ the fixing point of the link mechanism and (P ₅ in the figure), cross connection of right or left P ₅ or P ₁ (in the figure P _1), for example, When the arrow rotates counterclockwise, the other cross connection parts P ₂ , P ₃ , and P ₄ also rotate at the same phase and the same rotation speed as the cross connection part P ₁ .

[0056] Figure 19 is a diagram for explaining the state of rotation of the cross-connection of the third embodiment of the link mechanism shown in FIG. 18, the link indicated by the solid fixing the cross coupling portion P ₅ of the right end and, when the center O ₁ of the drive circle S ₁ when the cross-linking portion P ₁ of the left end is driven is on the straight line P ₁ P ₅ state, and a dotted line cross coupling portion P ₁ on the driving circle S ₁ 90 °, 180 °, 27
The position of each link when rotated by 0 ° is shown.

One end of the cross connection part of the link, for example, P
₅ was a fixed point, when the cross linking portion P ₁ of the other end side is rotated on the rotation circle S ₁ in the arrow direction, similar to the link shown in FIG. 13, other cross-linking portion P _2, P ₃ and P ₄ are rotated on the rotating circles S ₂ , S ₃ and S ₄ at the same phase and the same rotational speed as the cross connection part P ₁ . The ratio of the radii of the rotating circles S ₁ , S ₂ , S ₃ , S ₄ is 4: 3: 2: 1, and the centers O ₁ , O ₂ , O ₃ , O ₄ are arranged at equal intervals.

Accordingly, a photosensitive member having a central axis at the centers O ₁ , O ₂ , O ₃ , and O ₄ arranged at equal intervals in a straight line is arranged.
The center O ₂ , O ₃ , O ₄ as well as the center O ₁ and the cross connection point P ₁
And _four cross-connecting portions P ₂ , P ₃ , and P ₄ are rotatably connected to each other by an arm-shaped or disk-shaped support member (not shown) (corresponding to claim 5). Can be rotated in the same phase and at the same rotation speed.

[Embodiment 4] FIG. 20 is a view for explaining a link mechanism which is the basis of a link mechanism according to a fourth embodiment of the present invention. Two equal equilateral quadrangles shown in FIG. The center of the cross connection part of the link mechanism having a fixed point,
The movement of the link mechanism when any one of the other cross-connecting portions is rotated is shown. The solid line indicates the link mechanism before the movement, and the dotted line indicates the link mechanism when rotated 180 °.
Cross connecting portion P ₂ fixed points and with two trapezium-shaped point of P ₂
Are always equal and the straight line P ₁ P ₂ = P ₂ P ₃ ,
When one cross connection part, for example, P ₁ is rotated on the rotation circle S ₁ , the other cross connection part P ₃ is advanced by 180 ° and rotated at the same rotation speed as the cross connection part P _1. .

FIG. 21 is a sectional view of the link mechanism shown in FIG.
Example in the case of adding a link mechanism to the side and extending horizontally
FIG. 4 is a diagram for explaining a link mechanism of No. 4; As shown in FIG.
Link mechanism has four equilateral quadrilaterals P₁R₁P_TwoQ₁, P
_TwoR_TwoP_ThreeQ_Two, P_ThreeR_ThreeP_FourQ_Three, P_FourR_FourP_FiveQ_FourSide by side
Installed, cross connection part P₁, P_Two, P _Three, P_Four, P_FiveIs a straight line
Because it is on the top, the cross connection point P₁, P_Two, ~, P_FiveAre equally spaced
Are located in

The center cross connection part P ₃ is a fixed point, and the cross connection part P ₁ on _one end is located at the center O on the side of the fixed point P ₃ of the straight line P ₁ P _5.
When rotated in the counterclockwise direction of the arrow along the rotating circle S ₁ having ₁ , the cross connection portion P ₂ on the same side from the fixed point P ₃ has a radius of (１ ／) of the rotating circle S _1. rotation circle S ₂ on the cross-connecting portion P ₁ and the same phase, are rotated at the same rotational speed, crossing connecting portion opposite from the fixed point P ₃ P _4, P ₅ is rotated circle advanced with 180 ° phase It is rotated on S ₃ and S _{4 at the} same rotational speed as the cross connection part P ₁ .

In the link mechanism having four equilateral quadrangles shown in FIG. 21, the distance M2 between the centers O ₂ and O ₃ in the left and right rotating circles S ₂ and S ₃ sandwiching the fixed point P ₃ is fixed. Since the distance between the centers O ₁ and O ₂ and the distance M ₁ between O ₃ and O ₄ of the rotating circle on the same side with respect to the point P ₃ is twice as large, the link mechanisms are arranged at equal intervals. It cannot be used to drive the photoconductor. In order to rotate the photoconductors arranged at equal intervals at the same speed, it is necessary to change the length of the link, the cross connection position, and the like.

FIG. 22 is a view for explaining an example of another link mechanism in which the central cross connection portion is fixed.
Is a long link, and D is a short link. Portions that perform the same operations as in FIG. 5 are given the same reference numerals as in FIG.

The long link C has a length of 3 L
The links C ₁ , C ₂ , C ₃ , C ₄ of the book and the short link D
Are four links D ₁ , D ₂ , ₂ L each of length
D _3, ~, consist D _6, long links C _1, C ₂ and C _3, C ₄ are rotatably connected to intersect at the position of the position P ₂ and P ₄ of length 2L, cross coupling portion P _2, composed of P _4. The short links D ₁ and D ₂ are the free ends R ₁ and Q ₁ with the links C ₁ and C ₂ , respectively, and the links D ₅ and D ₆ are the links C ₃ and
Two quadrilaterals P ₁ R ₁ P ₂ Q ₁ and P ₄ R ₄ P which are rotatably connected to C ₄ by free end connecting portions R ₄ and Q ₄ and have a side length of 2L.
₅ Q ₄ is configured.

The other free ends of the links C ₁ , C ₄ and the links C ₂ , C ₃ are rotatably connected to the links D ₄ , D ₃ whose centers are rotatably crossed at a fixed point P ₂ , Free-end connecting portions R ₂ , Q ₂ and R ₃ , Q ₃ are formed, and two quadrilaterals P ₂ R ₂ each having a length L of four sides and having the fixed point P ₃ as a common term point
P ₃ Q ₂ and P ₃ R ₃ P ₄ Q ₃ are formed. As a result, the distance between the between and cross linking portion P ₁ and P ₂ and P ₄ and P ₅ of the fixed point P ₃ crossing connecting portion P ₂ and P ₄ sandwiching the are equal.

[0066] secured rotatably fixed point P ₃ to the apparatus main body, cross-connections of the links one end, for example, when rotated in the arrow counterclockwise direction P ₁ on turning circle S _1, fixed point P cross-connections of the same side with respect to ₃ P ₂ is the Kaidoen S ₁ radius (1/3)
Of the upper rotating circle S ₂ having a radius, P ₁ and the same phase, to rotate at the same speed, likewise, cross-linked portion P _4, P ₅ is Kaidoen S _3, S ₄
Phase from the intersection connecting portion P ₁ and is rotated at the same speed advanced 180 °.

As described above, the central cross connection portion P _{3 of} the cross connection portions P ₁ ,..., P ₅ arranged in a row as shown in FIG.
In the link mechanism fixed to the apparatus body side, the other cross-connecting parts P ₁ , P ₂ , P ₄ , P ₅ and the axes O ₁ , O ₂ , O ₃ , O _{4 of the} photoconductors ₁ , ₂ , ₃ , ₄ Are rotatably mounted by arm-shaped or disk-shaped cross members 5, 6, 7, and 8.
), The photoconductors 1, 2, 3, and 4 can always be rotated at the same rotational speed. Next, a rotation transmission mechanism that drives a plurality of photosensitive members arranged on a line via the link mechanism described in the fourth embodiment will be described.

FIG. 23 is a view for explaining an example of a rotation transmitting mechanism for rotating and driving the photosensitive member of the color image forming apparatus according to the present invention. FIG. 23 (a) is a partial perspective view, and FIG.
(B) is a sectional view taken along the line XX, in which 10 is a drive motor, 11 is a drive gear, 12 is a driven gear, 13 is a connecting shaft, 14 is a bearing, and 15 is an E-ring, which is shown in FIG. FIG. 5 shows a case where a link mechanism is used.
Portions performing the same operations as in FIG. 5 are denoted by the same reference numerals as in FIG.

For the sake of simplicity, FIG. 23 shows only two cylindrical photosensitive members, a first photosensitive drum 1 and a second photosensitive drum, and omits the others. The shafts 1a and 2a protrude from the centers of the first photosensitive drums 1 and 2, and one ends of lever-shaped support members 5 and 6 are fixed to the shafts 1a and 2a, respectively. As shown in FIG.
The free end connecting portions Q ₁ and Q _{2 of} the long link A ₁ and the short link B ₁ shown in FIG.

The mechanism for rotatably connecting the links is as follows.
For example, link A ₁ and B _1, as shown in FIG. 23 (b), is rotatably connected with the connecting shaft 13 having a shaft having different diameters of the two stages. In FIG. 23 (b), the bearing 1 or link B ₁ for supporting the large-diameter portion 13a of the connecting shaft 13
4, the link B is rotatably connected to the connection shaft 13. The small diameter portion 13c of the connecting shaft 13 is fixed by caulking or the like to link A _1, E-ring 1 and the link A ₁ and B ₁ fitted in the ring groove 13b of the connecting shaft 13
The movement in the axial direction is regulated by 5 and the joint is rotatably joined.

At an arbitrary position outside the first photosensitive drum 1, a drive motor 10 is mounted on the apparatus main body side (not shown) coaxially with the first photosensitive drum 1, and the drive motor 10 is driven by an axis. The gear 11 is fixed, and the drive gear 11 meshes with a driven gear 12 attached to the shaft 1 a of the first photosensitive drum 1.

When the drive motor 10 is driven to rotate, the first photosensitive drum 1 is rotated clockwise by an arrow via a drive gear 11 and a driven gear 12. When the first photosensitive drum 1 rotates, the support member 5 also rotates in the same direction. At the same time, the second photosensitive drum 2 uses a link mechanism including links A ₁ , A ₂ , B ₁ , B ₂ . 6 through the first photosensitive drum 1
And at the same rotational speed. Drive motor 10
The drive of the driven gear 11 by the photosensitive drum is not limited to the first photosensitive drum 1 side. Any other photosensitive drum may be used. Further, the driven portion of the photoconductor by the drive motor 10 is not limited to the link mechanism shown in FIG. 5, but is connected to any of the link mechanisms described in the first to fourth embodiments (corresponding to claim 7).

The photosensitive member of the color image forming apparatus according to the present invention is driven via a link mechanism having a plurality of links,
The link mechanism connects a plurality of links such that opposing sides form an equilateral quadrilateral, and uses one end of the connected links as a fixed end, and another connection existing on a straight line including the fixed end. Since the ends are completely synchronously rotated, good driving can be performed without generating vibration, noise, rotation unevenness, and the like that occur in the conventional photosensitive member driving method using a worm gear, a belt, and the like. In addition, the use of the link mechanism has an advantage that no oil replenishment is required at all for worms, gears, and the like. Furthermore, there is a great merit that the cost of parts can be much lower.

[0074]

As is apparent from the above description, the present invention has the following effects. According to the first aspect of the present invention, since the plurality of photosensitive drums are connected only by the link mechanism, the life of the apparatus can be reduced without being affected by dust and dust, which have been a problem with conventional worms, gears, belts, and the like. Increase significantly. Advantageous Effect According to Claim 2: The number of members (photosensitive drums in the present invention) connected to and driven by the links can be easily increased only by increasing the number of the links. According to the third aspect of the invention, only the fixed portion of the link mechanism is fixed to the apparatus body, and the other free end connecting portion of the link mechanism is connected to the support member of the photosensitive drum. Therefore, assembly can be easily performed. Advantageous Effect Corresponding to Claim 4: By setting the center of the plurality of free connection portions of the link mechanism as the fixed portion, a compact arrangement is possible without requiring extra spaces on the left and right. Further, since the left and right phases are shifted by 180 °, the load applied to the drive shaft becomes more uniform than that of the same phase. Effect corresponding to claim 5: A compact arrangement is possible without requiring extra space in the vertical direction. Advantageous effect corresponding to claim 6: A compact arrangement is possible without requiring extra spaces in the upper, lower, left and right directions. Advantageous Effect According to Claim 7: Since there is a high degree of freedom in the arrangement of the drive motors, the layout is not restricted and a compact arrangement is possible.

[Brief description of the drawings]

FIG. 1 is a view for explaining a link mechanism which is a basic of a first embodiment of a link mechanism for synchronously driving a photosensitive member in a color image forming apparatus according to the present invention.

FIG. 2 is a view for explaining an operation of the link mechanism shown in FIG. 1;

FIG. 3 shows the link mechanism shown in FIG.
It is the one when they are connected.

FIG. 4 is a view for explaining the operation of the link mechanism shown in FIG. 3;

FIG. 5 is a view for explaining an example of a drive mechanism for driving a photoconductor using the link mechanism shown in FIG. 3;

FIG. 6 is a view for explaining a link mechanism which is a basis of a link mechanism according to a second embodiment of the present invention.

FIG. 7 “Rotation start” of the link mechanism shown in FIG. 6
FIG. 4 is a diagram for explaining the state of FIG.

FIG. 8 is a view for explaining a state where the link mechanism shown in FIG. 6 has been “turned by 90 °”;

FIG. 9 “180 ° rotation” of the link mechanism shown in FIG. 6
It is a figure for explaining the state where it did.

FIG. 10 is a view for explaining a state where the link mechanism shown in FIG. 6 has been “rotated by 270 °”.

FIG. 11 is a diagram for explaining a link mechanism in which a plurality of link mechanisms according to the second embodiment shown in FIG. 6 are arranged in a horizontal direction.

12 is a diagram for explaining an example of a drive mechanism that drives a photoconductor using the link mechanism shown in FIG.

FIG. 13 is a view for explaining a link mechanism which is a basis of a third embodiment of the link mechanism according to the present invention.

FIG. 14 is a view for explaining a state of “rotation start” of the link mechanism shown in FIG. 13;

FIG. 15 is a view for explaining a state where the link mechanism shown in FIG. 13 has been turned “90 °”.

FIG. 16 is a view for explaining a state where the link mechanism shown in FIG. 13 has been “180 ° rotated”;

FIG. 17 is a view for explaining a state where the link mechanism shown in FIG. 13 has been “rotated by 270 °”.

FIG. 18 is a view for explaining a link mechanism according to a third embodiment in which the link mechanisms shown in FIG. 13 are arranged side by side.

FIG. 19 is a view for explaining a state of rotation of a cross connection part of the link mechanism according to the third embodiment shown in FIG. 18;

FIG. 20 is a diagram illustrating a link mechanism that is a basis of a fourth embodiment of the link mechanism according to the present invention.

FIG. 21 is a view for explaining a link mechanism according to a fourth embodiment in which both sides of the link mechanism shown in FIG. 20 are extended.

FIG. 22 is a view for explaining an example of another link mechanism of the fourth embodiment in which the central cross connection portion is fixed.

FIG. 23 is a view for explaining an example of a rotation transmitting mechanism for rotating and driving the photoconductor of the color image forming apparatus according to the present invention.

FIG. 24 is a diagram illustrating an example of a color image forming apparatus to which the present invention is applied.

[Explanation of symbols]

Reference numerals 1, ..., 4 ... Photoconductor, 5, ..., 8 ... Support member, 10 ... Drive motor, 11 ... Drive gear, 12 ... Driven gear, 13
... connecting shaft, 14 ... bearing, 15 ... E-ring.

Claims (7)

(57) [Claims] 1. A photoconductor comprising a plurality of photoconductors arranged in a straight line, and conveying means for conveying a recording sheet linearly along the photoconductor, wherein the photoconductor is exposed when the recording sheet passes through the photoconductor. In an image forming apparatus for visualizing an electrostatic latent image formed on a body and transferring the latent image on a recording sheet, the photosensitive members arranged adjacent to each other are rotatably supported by a plurality of linked link mechanisms. A color image forming apparatus, comprising: 2. A plurality of two linked links, each having a cross-connecting portion that is rotatably cross-connected to the plurality of connected link mechanisms, are arranged side by side, and the opposing free ends of each of the links are rotated. 2. A plurality of free end connecting portions which are freely connected to each other, and opposing sides of a quadrilateral formed by the links are equal in length.
3. The color image forming apparatus according to 1. 3. One of right and left ends of the free end connecting portions of the link mechanisms arranged in a row is rotatably supported by the apparatus main body, and another free end connecting portion is provided on the photoreceptor shaft. The color image forming apparatus according to claim 1, wherein the color image forming apparatus is rotatably attached to a supported supporting member. 4. A center end of the free end connecting portions of the link mechanisms arranged in a row is rotatably supported by the apparatus body, and another free end connecting portion is supported on the photoreceptor shaft. The color image forming apparatus according to claim 1, wherein the color image forming apparatus is rotatably attached to the supporting member. 5. One of right and left ends of the cross connection portions of the link mechanisms arranged in a row is rotatably supported by the apparatus body, and the other cross connection portion is supported on the photoreceptor shaft. The color image forming apparatus according to claim 1, wherein the color image forming apparatus is rotatably attached to the supporting member. 6. A central portion of the cross connection portions of the link mechanisms arranged in a row is rotatably supported by the apparatus body,
2. A cross-connecting portion rotatably attached to a support member supported on the photoreceptor shaft.
Or the color image forming apparatus according to 2. 7. A driven portion for transmitting power from a drive motor to one of the plurality of photoconductors connected to the link mechanism via the support member is fixed. The color image forming apparatus according to any one of claims 1 to 6, wherein: