JPS62109472A - Original reader - Google Patents

Abstract

PURPOSE:To secure the application such as a rotary motor, an encoder which are put on the market with reasonable prices by converting the revolutions of a rotary motor into the stable linear shift motions and driving an original reading unit. CONSTITUTION:An original reading unit 1 is moved in a scan direction with the revolution of the output shaft 6 of a rotary motor 2. Thus the magnetic sucking force acts on the contact face between a roller 8 containing a permanent magnet 8c and an iron guide rail 9. As a result, the frictional force is produced and the roller 8 is rolled on the rail 9 to produce a linear motion. Here bearings 13 and 14 have the pressure contacts to the lower face of the rail 9 to keep a state where the rail 9 is held between the roller 8 and both bearings 13 and 14. As a result, the unit 1 is driven along the rail 9 stably without falling, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a document reading device such as an image scanner of a digital copying machine or a mirror scanner of a normal copying machine.

BACKGROUND ART In general, in this type of document reading device, an image is read by scanning the document surface with a document reading unit equipped with, for example, a fluorescent lamp, a lens array, a CCD image sensor, etc. There is. As a driving method for this document reading unit, it is common to move it on a rail using a drive wire, a timing belt, etc. together with a motor, a pulley, etc. However, in the case of such a wire drive method, the structure tends to be complicated and the cost tends to increase.

In this regard, some scanners have a document reading unit mounted on a movable member of a linear motor.

This is r National Technica
l Report Vol, 30. No, 6. DEC1
This is known as an image scanner in 984J.

However, in this method, a large vertical nozzle J occurs between the movable element and the stator of the linear motor (linear pulse motor). Therefore, there is a need to increase the mechanical rigidity of the mover body, the guide rail, the bearings and shafts of the mover.

Therefore, members such as the mover main body must be made of high-rigidity metal to ensure rigidity, or they must be formed using a large amount of metal to increase mechanical rigidity, resulting in increased cost or weight. It is something. In addition, the configuration of the position sensor for controlling the position is complicated, and a uniform gap cannot be obtained over a long stroke (traveling distance).
The reliability of the signal is low and the accuracy is also poor. Furthermore, the characteristics of the motor vary depending on the position on the stator, making it difficult to obtain precise constant velocity characteristics. In addition, magnetic noise has also become large. Furthermore, since the document reading unit is mounted on the movable member, the device cannot be made thinner.

OBJECTS The present invention has been made in view of the above points, and an object of the present invention is to provide a document reading device that can be made thin and compact at low cost, and can reduce magnetic noise.

Structure: In order to achieve the second object, the present invention provides a document reading device in which a document reading unit scans a document surface and reads an image, and includes a rotary motor having an encoder on an output shaft for controlling the rotation speed. The rotary motor is mounted so as to be positioned substantially in the same plane as the original reading unit, and a rotary roller with a built-in permanent magnet is integrally formed on the output shaft of the rotary motor, and the rotary roller is aligned along the scanning direction. bearing members are disposed on a magnetic guide rail, each rotatably mounted on a plurality of fixed shafts having spring properties extending from the document reading unit, and in pressure contact with the lower surface of the guide rail. It is characterized by this.

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. First, fluorescent light, lens array, CCD
A document reading unit 1 having a built-in image sensor and the like is provided.

This document reading unit 1 reads a document image by reciprocating the document surface in the left-right direction. A rotary motor 2 is mounted at one end of this document reading unit 1.
and encoder 3 are installed coaxially. This rotary motor 2 has a movable element 5 in a stator 4 for DC servo, and an output @116 is taken out from this movable element 5, and the encoder 3 is fixed to one end of this output 1 to 6. has been done. A sensor 7 is arranged on the encoder 3. On the other hand, a rotating roller 8 is fixed to the outside of the output shaft 6 of the rotary motor 2 by press-fitting or integral force. This rotating roller 8 has a flange 8b at one end of the roller portion 8a, and has a built-in permanent magnet 8c (the configuration of the permanent magnet 8c is, for example, shown in FIGS. 4(a) to 4(a)).
(C).

The roller portion 8a of the rotating roller 8 is arranged on a flat guide rail 9 along the scanning direction of the document reading unit 1. This guide rail 9 is made of iron or the like and has magnetism. On the other hand, a fixed shaft 1 is disposed coaxially with the output shaft 6 on the other end side of the document reading unit 1.
o has been taken out, and a grooved bearing 11 is installed. This bearing 11 is arranged on a guide rod 12 parallel to the guide rail 9. Both ends of these guide rails 9 and guide rods 12 are fixed to the main body of the apparatus (not shown).

On the other hand, two bearings 13 as bearing members are attached to the lower surface of the guide rail 9. ] 4 are provided spaced apart in the scanning direction.

These bearings 13, 14 are attached to a fixed shaft 17 extending outwardly from a flange 15, 16 fixed to the casing of the rotary motor 2 (and thus to the document reading unit 1).
, 1.8. Here, the bearings 13, 14 are pressed into contact with the lower surface of the guide rail 9 by having these fixed shafts 17, 18 themselves having spring properties, or by providing a spring mechanism in the flanges 15, 16. Further, at the other end of the document reading unit 1, a bearing 19 is also provided on the lower surface of the guide rod 12. Second bearing 1
9 is rotatably mounted on a fixed shaft 20 extending from the document reading unit 1, and is brought into light pressure contact with the lower surface of the guide rod 12 due to the spring properties of the fixed shaft 20.

In such a configuration, the document reading unit 1 moves in the scanning direction as the output shaft 6 of the rotary motor 2 rotates. In this case, it is necessary to convert the output of the rotary motor 2, that is, the rotational force of the output shaft 60, into linear movement force. In this respect, at the contact surface between the rotating roller 8 containing a permanent magnet 80 and the iron guide rail 9, an attractive force acts, a frictional force is generated, and the rotating roller 8 rotates while moving the guide rail 9. Since it moves on the guide rail 9, there is a linear motion.At this time, the bearing 13.
14 are in suppressed contact, the state in which the guide rail 9 is held between the rotating rollers 8 and the bearings 13 and 111 is maintained, so that the document reading unit 1 can move along the guide rail 9 without falling over. and drive stably. Note that the bearing 19 has a function of regulating the vertical movement of the entire document reading unit 1. Also, the manuscript reading unit
-]'s lateral movement is regulated by the collar 8b of the rotating roller 8 and the groove 2 of the bearing 11. As for the control system, the operation of the rotary motor 2 is feedback-controlled based on the output signal of the encoder 3 directly connected to the output shaft 6 of the rotary motor 2, so that the document reading unit 1 is controlled to run at a constant speed. be done. As such feedback control, the well-known F/V control method, PLL control method, or a combination thereof is sufficient.

In order to generate more reliable frictional force, both surfaces or one surface of the frictional contact surface between the rotating roller 8 built in the permanent magnet 8c and the guide rail 9 should be made into a resin friction material film structure. This makes it possible to convert rotational force without slippage into linear movement force.

As described above, according to this embodiment, commercially available inexpensive rotary motors 2 and encoders 3 are sufficient, and the kite rails 9 and guide rods 12 are also low-cost products that can be mass-produced. , the overall cost is low. The document reading unit 1, the rotary motor 2, and the encoder 3 are coaxially arranged in a linear manner, and the device is
It can be made into a small type. Furthermore, if a coreless motor is used as the rotatable motor 2, precise constant speed performance with low noise and no cogging torque can be obtained.

Furthermore, if a five-phase step motor is used as the rotary motor 2, for example, the encoder 3 can be omitted, making it possible to further reduce costs. However, in this case, some magnetic noise will be generated and the constant speed will be poor.

In this embodiment, the document reading unit 1, the encoder 31, and the rotary motor 2 are arranged in this order, but the encoder 3 may be arranged outside as shown in FIG.

Continuing, the second embodiment of the present invention will be explained in the sixth and seventh embodiments.
This will be explained using figures. The same parts as those shown in the previous embodiment will be explained using the same reference numerals. In the second embodiment, the arrangement is changed, and the rotary motor 2 is attached with the output shaft 6 vertically perpendicular to the longitudinal direction of the original reading unit 1. Thereby, the encoder 3 is also attached above (or below) the rotary motor 2. Then, since the rotating roller 8 on the output shaft 6 is in a horizontal state,
■ It has a grooved structure, and ■ It is engaged with the chevron portion of the iron guide rail 9 with chevrons. The rotating roller 8 has a built-in permanent magnet 8c, for example, as shown in FIGS. 7(a) and 7(b). The bearings 13 and 14 are in pressure contact with the guide rail 9 from the outside.

Even with such a configuration, the same effects as in the embodiment described above can be obtained.

Note that the relationship between the rotating rollers 8 and the guide rail 9 may be reversed, and grooves may be formed on the guide rail 9 side, and chevron-shaped rotating rollers 8 as shown in FIG. 8 may be used to engage with the grooves. .

Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the rotary motor 2 and the encoder f3 are attached to the lower side of the document reading unit 1 in parallel in plan view, and the output shaft 6 of the rotary motor 2 is taken out on both sides. Rotating rollers 8 are mounted on guide rails 9 and guide rods 12 with narrower spacing.

In this case, the guide rod 12 is also made of iron, and the rotating rollers 8 for this guide rod 12 have a V-groove structure. According to this embodiment, since the linear movement force is generated on both sides, reliability can be further improved than in the case of one side.

Further, FIG. 10 shows a fourth embodiment of the present invention. In this embodiment, in the third embodiment, the spacing between the guide rail 9 and the guide rod 12 is the same as in the first embodiment, and the output shaft 6 of the rotary motor 2 is extended to both ends of the document reading unit 1. It is something that In this case, the rotary motor 2 and the encoder 3 are mounted in parallel above the document reading unit 1.

Furthermore, a fifth embodiment of the present invention will be explained with reference to FIG. This embodiment is applied to a mirror scanner in a normal PPC copying machine or the like. That is, in a PPC copying machine, the system is divided into a first mirror optical system and a second mirror optical system, and if the first mirror optical system moves at a speed of V, the second mirror optical system moves at a speed of v/2. There is a need to. Therefore, in this embodiment, the original reading unit 11 is equipped with the V-th mirror optical system member, and the original reading unit 1 is equipped with the second mirror optical system member. Rotary motors 25, 2□, encoders 33, etc. are linearly attached to each of the rotary rollers 8. and 8.3, respectively, as in the case of the first embodiment. , 81, etc.

According to this, the rotary motor 2. , 2. By individually controlling the original reading unit with the speed relationship of 2.1]
, , , 12 can be moved in a straight line.

Effects Since the present invention is configured as described above, it is possible to stably convert the rotational motion of the rotary motor into linear motion to run the original reading device, and it is generally used as a rotary motor, encoder, etc. Commercially available inexpensive ones can be used, and the cost of the entire device can be reduced.Also, since these rotary motors and encoders are mounted on the same plane as the document reading unit,
The device can be made thinner, and furthermore, it can be run with reduced magnetic noise.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing an enlarged main part of a first embodiment of the present invention, FIG. 2 is a schematic perspective view, and FIG. 3 is a schematic side view.
4(a) to 4(c) are cross-sectional views of the rotating roller, FIG. 5 is a schematic side view showing a modified example, FIG. 6 is a schematic side view showing a second embodiment of the present invention, and FIG. 7 is a schematic side view showing a second embodiment of the present invention. (a) to (b) are cross-sectional views of a rotating roller, FIGS. 8(a) to (1)) are cross-sectional views of a rotating roller showing a modification, and FIG. 9 is a third embodiment of the present invention. FIG. 10 is a schematic perspective view showing a fourth embodiment of the present invention, and FIG. 1I is a schematic perspective view showing a fifth embodiment of the present invention. 1. Original reading unit, 2... Rotary motor, 3
・Encoder, 6... Output shaft, 8... Rotating roller, 8
(Permanent magnet, 9... Guide rail, 13.14...
Bearing (bearing member), 17.18...Fixed shaft 3.1 Figure 5.3 (To D -' N--

Claims (1)

[Claims] In a document reading device that scans a document surface to read an image using a document reading unit, a rotary motor having an encoder for controlling the number of rotations on an output shaft is positioned substantially in the same plane with respect to the document reading unit. A rotary roller with a built-in permanent magnet is integrally formed on the output shaft of the rotary motor, and the rotary roller is placed on a magnetic guide rail along the scanning direction, and the document reading unit is mounted. What is claimed is: 1. A document reading device comprising: a bearing member rotatably mounted on a plurality of fixed shafts having spring properties extending from the guide rail, each bearing member being in pressure contact with the lower surface of the guide rail;