JPS60196423A - Medium driving mechanism - Google Patents

Abstract

PURPOSE:To make such transmission as being ease of separation and coupling and that accuracy performable, by performing the transmission of driving force between both upper and lower units in a way of pressing a roller installed in the upper unit to a timing belt installed in the lower unit. CONSTITUTION:When an upper unit is lifted up, a pulley 26 for drum use is made to go up whereby tension of a both-side toothed belt 30 gets loosening. At this time, a tension pulley 31 on a shaft 34 of a pulley support arm 33 supported by a guide pin 32 moves to some extent by dint of tension of a spring 35, preventing the belt from coming off an intermediate pulley 25 and guide pulleys 28 and 29. Next, when the upper unit is brought down, the pulley 26 for drum use moves downward whereby teeth of the pulley for drum use and teeth of the both-side toothed belt 30 are engaged with each other, thus driving force is transmittable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a medium drive mechanism used in a high resolution image output device.

(Prior Art) A conventional device is shown in FIGS. 1 and 2. FIG. 1 shows the state during normal image output, and FIG. 2 shows the state when paper jams can be removed.

1 is a photosensitive drum that rotates in the direction of the arrow shown in the figure; 2 is a charging device; 3 is an exposure device; 4 is a developing device; 5 is a transfer charging device; 6 is a cleaning device; and 7 is an electrophotographic fixing device. This device can be roughly divided into an upper unit 8 and a lower unit 9. The lower unit 8
The lower unit 9 can be opened and closed about the fulcrum 10, and the closed state is shown in FIG. 1, which is the state at the time of image output. The opened state is shown in FIG. 2, and the transfer paper 11 can be removed in the event of a jam.

Reference numeral 12 denotes a motor for driving the photosensitive drum 1, which is a synchronous motor with less uneven rotation, and is attached to the lower unit due to the structure of the apparatus.

-T: -The rotation of the gear 12 is transmitted from the motor belt 14 to the intermediate pulley 15 via the timing belt 13, and reaches the intermediate gear 16 which is integrated with the intermediate pulley 15. At the time of image output as shown in FIG. 1, a drum gear 17 integrated with the photoreceptor drum I meshes with the intermediate gear 16, and the rotation of the motor 12 is finally transmitted to the photoreceptor drum I.

The transfer paper 11 is fed from a cassette 18, is fed in the direction of the arrow shown in FIG. 1, transfers the toner image on the photosensitive drum I by the transfer charger 5, passes through the fixing device 7, and becomes a permanent image.

In this apparatus, if the transfer paper 11 jams during recording in the image output state shown in FIG. 1, it is necessary to remove the transfer paper 11. Therefore, in order to remove the jammed transfer paper 11, the upper unit 8 is moved to the fulcrum L as described above.
It has a structure that can be opened upwards centering on O, and for the same reason, the photoreceptor drum 1 is placed on the upper unit 8 side so that the transfer paper 1 can be removed even if it jams below the photoreceptor drum 1. The structure is such that it can be installed and raised together with the upper unit 8 in both directions. At this time, the drum gear 17 that had been meshing with the intermediate gear 16 is also separated,
The rotation of the motor 12 can no longer be transmitted to the photosensitive drum 1.

Next, to explain the transition from the state shown in FIG. 2 to the image output state shown in FIG. 1, when the upper unit 8 is lowered around the fulcrum 10, the upper unit, l. In the locked state, the drum gear 17 and the intermediate gear 16 are configured to mesh again, returning to a state where the rotation of the motor 12 can be transmitted to the photosensitive drum 1.

In this apparatus, as described above, when the transfer paper 11 jams, the upper unit 8 must be able to be raised so that it can be removed, and the photosensitive drum I must also be raised at the same time. The rotation transmission section 4 between the rotary motor 12 and the photoreceptor drum 1 is easily separated when the upper unit 8 is opened, and easily engaged when the upper unit 8 is closed.
It is necessary to be able to accurately transmit the rotation of the A gear transmission is generally used as a transmission member for the purpose described in -, and is also used in this device.

However, since gears are used for the drive transmission member, the photoreceptor drum I due to the influence of gear pack latitude.
There is slight unevenness in rotation.

On the other hand, in the electrophotographic exposure process of this apparatus, the exposure device 3 photoelectrically converts the image electrical signal and sequentially exposes one line in the main scanning direction in synchronization with an electrically regular clock signal 19. .

As explained in Section 2 below, in the exposure process, one line in the main scanning direction is exposed on the photosensitive ram 1 in a temporally regular manner in synchronization with the clock signal 19, whereas 10 rotations of the photosensitive drum is performed by a gear shift. Rotation unevenness occurs due to backlash, so when an image is output, the interval between one main scanning line and one line becomes narrower or wider.

Therefore, in areas where the line spacing is dense (d density is high, areas with sparse lines appear thin, noise in the form of a striped pattern of shading occurs in the sub-scanning direction, resulting in extremely poor image quality.)
5) The narrower the line interval, that is, the higher the resolution, the more noticeable the difference becomes, and the higher the resolution, the more difficult it becomes to resolve the problem.

(Object of the Invention) In order to solve these drawbacks, the object of the present invention is to use a timing bell with no backlash as a drive transmission member between the upper unit and the lower unit, and to easily separate and connect them. This will be explained in detail below.

(Structure of the Invention) To explain the structure of FIGS. 3 and 4, 21 is a motor, which is a synchronous motor with little rotational unevenness, 22 is fixed to the shaft of the motor 21, and 23 and 25 are intermediate motors. At boo IJ, the motor nori 22 and the intermediate pulley 23 are connected by a timing bell j.24, and the intermediate pulley 2
Rotation is transmitted to 3. Reference numeral 26 denotes a drum pulley which is integrated with the photosensitive drum 27. 28 and 29 are idle pulleys provided on both sides of the drum pulley 26;
0 is a toothed belt on both sides, with an intermediate pulley 25 and a guide (6); The rotation is transmitted to the drum pulley 26.

The shaft 3 stands on the IJ support arm 33, which can be rotated around the guide pin 32 using a 31-piece tension pulley.
A spring 35 is hung on one end of the shaft 34, and the other end of the spring 35 is hung on a spring pin 36.

Next, the operation of the structure described above will be explained. When the transfer paper 37 jams in the operating state shown in FIG. 3, the upper unit is lifted upward in the same manner as in the conventional apparatus. At this time, the photoreceptor drum 27 and the drum pulley 26 are also raised together with the upper unit as shown in FIG.
The structure is such that even if the transfer paper 37 becomes jammed below, it can be removed.

As mentioned above, when the upper unit is raised, the drum pulley 2
6 is also raised and the tension (7) of the toothed belt 3o on both sides begins to loosen, the tension pulley 31 on the shaft 34 of the pulley support arm 33 supported by the guide pin 32 is moved by the tension of the spring 35 as shown in FIG. Even if the drum pulley 26 is moved to the -F direction after the drum pulley 26 is moved to the -F direction, an appropriate tension is always applied to the toothed belts 30 on both sides to prevent the intermediate pulley 25 from coming off the idler pulleys IJ2B and 29. It is prevented.

Next, to explain the state when the state transitions from the state shown in FIG. 4 to the recording operation shown in FIG. 31, the teeth of the toothed belt 30 on both sides mesh with each other, and finally return to the state shown in FIG. 3 during the recording operation.

As explained above, in the embodiment of the present invention, the relative position of the motor and the photoreceptor drum is determined by the mechanism using the toothed belt on both sides as a drive transmission member between the motor and the photoreceptor drum when outputting an image as shown in FIG. Both the position and the position for taking out the transfer paper in the event of a jam can be easily selected, and since the transmission member uses a rose flage and an imming belt (8), the rotation of the photosensitive drum 27 has very little rotational unevenness.

Therefore, when an image is output, the intervals between one line and one line are recorded at a regular interval of i~, making it possible to record with high resolution.

(Effects of the Invention) The present invention is applicable not only to electrophotographic recording devices as shown in the embodiments, but also to high-resolution output and input devices in which the transmission member can easily repeat separation and combination, and which requires accurate transmission. 0 available for equipment

[Brief explanation of the drawing]

FIGS. 1 and 2 are external views of a conventional apparatus, with FIG. 1 showing the state during recording operation and FIG. 2 showing the state when paper is removed in the event of a jam. 3 and 4 show a drum drive transmission mechanism according to an embodiment of the present invention, with FIG. 3 showing the state during recording operation and FIG. 4 showing the state during paper take-out. 1 is a photosensitive drum, 3 is an exposure device, 8 is an upper unit,
9 is the lower unit, 11 is the transfer paper, 12 is the motor, 16
is an intermediate gear, 17 is a drum gear, (9) 21 is a motor, 25 is an intermediate pulley, B126 is a drum pulley, 27 is a photosensitive drum, 28.29 is a force field pulley, 3θ is a toothed belt on both sides, 31 is a tension pulley. Patent applicant: Oki Electric T Gyo Co., Ltd. Nippon Telegraph and Telephone Public Corporation (]0) 1. Indication of the case 1982 Patent Application No. 050858 2. Name of the invention Media drive mechanism 3. Person making the amendment Relationship to the case Appointment of the patent applicant Address (105) 1-7-12 Toranomon, Minato-ku, Tokyo
Address (105) 1-7-1 Toranomon, Minato-ku, Tokyo
No. 2, No. 5, Subject of amendment Column “Claims” and “Detailed Description of the Invention” column 6 in the description Contents of the amendment As shown in the attached sheet 6 Contents of the amendment (1) “Scope of claims” in the description ” column as shown in the attached sheet. (2) In the 14th line of page 2 of the same book, the phrase "the lower part" is amended to read "the upper part." Attached Patent Claims: There is a timing belt on the driven side and a timing belt on the driving side, and one of the timing belts can easily reciprocate between two positions, a state in which transmission is possible and a state in which transmission is not possible. In a device capable of moving, in a transmission drive state, guide pulleys are provided on both sides of the pulley on the rotating side, and the pulley on the rotating side is engaged with the outside of the toothed belt on both sides, and the other pulleys are Inside and above both l111
Rotation can be transmitted from the drive side timing belt pulley to the driven side timing belt pulley by combining the rivers so that the toothed belt has a predetermined tension, and when driving, the rotation is transmitted from the outer side of the toothed belt on both sides. A medium drive mechanism characterized in that the pulley meshed with the belt can be easily disengaged from the double-side toothed belt and rotated to a position where no transmission is possible. -1171 pieces-

Claims (1)

[Claims] In a device that has a driven side timing belt pulley and a driving side timing belt pulley, and one of the pulleys can easily reciprocate between two positions, a transmission drive enabled state and a transmission disabled state, in the transmission drive state, Guide pulleys are provided on both sides of the pulley on the rotating side, and the pulley on the rotating side meshes with the outside of the toothed belt on both sides, and the toothed belt on both sides is set in a predetermined position with the other gies on the inside. Rotation can be transmitted from the driving side timing belt pulley to the driven side timing belt pulley by combining the hooks so as to have a tension of A media drive mechanism characterized by being able to detach from a toothed belt on both sides and rotate to a position where no transmission is possible.