JPH06208173A - Reciprocating device - Google Patents

Abstract

PURPOSE:To provide a reciprocating device capable of stably driving a carriage with high precision during the forward movement and driving it with high-speed, low torque during the return movement with one motor without using a high- speed, high-torque motor with a very simple structure. CONSTITUTION:A reciprocating device is provided with a carriage 8 mounted with an optical member, moving pieces 16, 17 fitted to the carriage 8, guide members 9, 10 supporting the carriage 8 in contact with the moving pieces 16, 17, extended in the reciprocating direction of the carriage 8, and guiding the forward movement and the return movement of the carriage 8, a pressing means 18 fitted to the carriage 8 and having a rotary member 19 kept in contact with the faces of the guide members 9, 10 opposite to the faces kept in contact with the moving pieces 16, 17 and a pressing member 20 pressing the rotary member 19 to the guide members 9, 10 side, and a rotation control means 26 disabling the rotation of the rotary member 19 of the pressing means 18 during the forward movement of the carriage and enabling the rotation during the return movement of the carriage 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating device for reciprocating a carriage equipped with a scanning optical system of an image reading device such as a scanner, a copying machine or a fax machine.

[0002]

2. Description of the Related Art Conventionally, as a method of supporting a carriage on which optical system parts are mounted on a pair of guide shafts arranged in parallel, a carriage is supported by a slide bearing or the like in a state of being almost fitted to the guide shaft. The method is roughly classified into a method and a method of supporting the guide shaft in a state of being mounted on the guide shaft by a sliding or rotating bearing. In the latter method as compared with the former method, the degree of freedom of the movement of the bearing is large, so that the restricting means is provided so that the carriage moves only in the moving direction. The restricting means is generally a method of restricting by sliding another sliding bearing on the lower side or the left and right sides of the guide shaft, or by providing a rotary bearing on the carriage and pressing it, and a wire or a wire on both the left and right sides of the carriage. One of the methods is adopted in which a belt or the like is stretched and regulated by driving it on both sides. Recently, such a regulation means is required, but the latter method is often used because of problems such as ease of assembly and play due to clearance between the guide shaft and the bearing. Therefore, a specific example of the method of supporting the carriage by the latter means will now be described.

First of all, as the first conventional example, Jitsuko Sho 5
There is one disclosed in Japanese Patent Publication No. 7-10845 under the name of "carriage holding device". This is because the rotary V-groove bearing and the rotary bearing mounted on the carriage are supported on the guide shaft to support the carriage, and the rotary V-groove bearing and the rotary bearing are The carriage is held on the guide shaft by pressing a rotatable roller against the surface of the guide shaft which is in contact with the guide shaft by using an urging mechanism, and thereby the movement of the carriage is controlled.

As a second conventional example, there is an application filed by the present applicant, which is disclosed in Japanese Patent Publication No. 53-40532 under the name of "precision holding device for movable member". This is because the roller is arranged on the upper side of the side surface of the carriage, and the roller is arranged below the upper roller, and the guide shaft is interposed between the upper and lower rollers to hold the carriage. The movement is controlled.

As a third conventional example, there is an application filed by the present applicant, which is disclosed in Japanese Utility Model Publication No. 57-25216 under the name "moving body holding device".
This is to provide a sliding type V grooved bearing and a roller provided with a biasing mechanism on the side surface of the carriage, and to hold the carriage by interposing a guide shaft between the sliding type V grooved bearing and the roller. By this, the movement control of the carriage is performed.

As a fourth conventional example, Japanese Patent Laid-Open No. 58-957.
No. 62 publication, "Scanning optical system drive mechanism in copying machines and the like"
There is something disclosed under the name. This is a sliding bearing similar to the third conventional example, in which two scanners are supported by slide members arranged on the lower surfaces of both sides and the wires stretched at both ends of the scanner are moved. The movement of the scanner is controlled by.

As a fifth conventional example, an actual Kaihei 4-2745 is used.
There is one disclosed in the publication No. 2 under the name "image forming apparatus". This is because two mirror frames are supported on the guide rails by rotatable rollers, and a one-way clutch is provided for those rollers so that the rollers cannot rotate when the mirror frame moves forward and can rotate when the mirror frame moves backward. Is set to control the movement of the mirror frame.

[0008]

When a rotary bearing is used as the bearing for supporting the carriage as in the first conventional example, the load (friction force) on the carriage can be reduced,
This is extremely advantageous for drive systems such as drive motors. However, the eccentricity of the rotary bearing, the slip of the rotary bearing with respect to the guide shaft, and the like are transmitted to the carriage side as load variations, causing speed variations. Such a carriage speed fluctuation is
In an image reading or image forming apparatus, since the reading accuracy and the image forming accuracy are greatly affected, particularly in the case of the rotary bearing, the processing accuracy thereof needs to be high.

In the case of the rotary type V-groove bearing, since the guide shaft is in contact with the guide shaft at two places so as to hold it,
If an error occurs in the diameter of the contacting portion, it appears as a difference in peripheral speed, which requires careful attention. Therefore, there is a second conventional example that solves the problem of the difference in peripheral speed due to the error of the diameter, but the problem of eccentricity or the like remains.

As a solution to the problems such as eccentricity, sliding with a guide shaft, and high precision machining, there are sliding type bearings such as the third conventional example and the fourth conventional example. As a result, the carriage can be easily driven with high precision with an inexpensive structure. However, in this case, since the guide shaft is slid, the load (friction force) of the carriage increases, and the load on the drive system such as the drive motor increases.

Further, like an image reading apparatus, in general, an image is read at the time of the forward movement of the reciprocating movement of the carriage,
When returning to the starting position only when returning to the starting position, high-accuracy driving is required when moving forward, and when returning to the starting position, high-accuracy driving is not required and only a quick return to the starting position is required. In particular, the speed of the backward movement is usually several times faster than the speed of the forward movement, so the drive system used, such as the drive motor, must be capable of high torque drive as well as high precision drive. I won't. Further, when the sliding bearing is used, the load applied to the drive system is further increased, so that a drive motor that generates a larger torque is required. Therefore, it is technically difficult to make the characteristics of the forward movement and the characteristics of the backward movement compatible with one drive motor, and it becomes very expensive. Therefore, in the past, drive motors having the respective characteristics have been obtained. Two of them are separately provided, and the driving is performed by switching each time of reciprocating movement.

In view of these two characteristics, therefore, there is a fifth conventional example in which a one-way clutch is attached to a roller (rotary bearing) to solve the problem. That is, by using one roller, the drive control is performed so that the sliding type bearing is used for the forward movement and the rotary type bearing is used for the backward movement, whereby highly accurate low speed driving is performed during the forward movement of the carriage and low torque is used during the backward movement. (Light load) It enables high-speed return of the drive. However, in this case, the roller used as the sliding bearing is often formed of a resin material in consideration of problems such as scratches and noise,
"Dent" due to friction or pressure at the contact part with the guide shaft
Will occur. If such a recess is not always located at the sliding portion (contact portion with the guide shaft), it becomes a major cause of load fluctuation (speed fluctuation) and carriage position error. In particular,
When the rotary bearing is repeatedly slid and rotated alternately, the position of the recess on the circumference may change each time it slides, or innumerable different recesses may occur. . For this reason, when the roller, which is a rotary bearing, is repeatedly slid and rotated alternately, it is necessary to control the position of the recess that occurs on the circumference. I can't find anything going on.

[0013]

According to a first aspect of the present invention, there is provided a carriage on which an optical member or the like is mounted, a movable element attached to the carriage, and a movable element that is in contact with the movable element to support the carriage and to support the carriage. In a reciprocating device provided with a guide member that extends in the reciprocating direction and guides the forward and backward movements of the carriage, a rotating member that is in contact with a surface of the guide member that faces the movable element is in contact A pressing unit having a pressing member that presses a rotating member toward the guide member is attached to the carriage, and the rotating member of the pressing unit cannot rotate when the carriage moves forward and can rotate when the carriage moves backward. Control means were provided.

According to a second aspect of the present invention, a carriage on which an optical member or the like is mounted, a movable element attached to the carriage, a movable element that is in contact with the movable element, supports the carriage, and extends in the reciprocating direction of the carriage. In the reciprocating device having a guide member for guiding the forward and backward movements of the carriage, at least one of the movers attached to the carriage is formed by a rotor, and Rotation control means is provided so as not to rotate when the carriage moves forward and to rotate when the carriage moves backward, and the outer peripheral length of the portion of the rotor that contacts the guide member is set to the movement distance from the start position to the return position of the carriage. The length was set to be equal to a fraction of an integer.

According to a third aspect of the present invention, in the second aspect of the invention, the outer peripheral lengths of the portions of at least two rotors that come into contact with the guide members and that come into contact with the guide members are set equal.

According to the invention of claim 4, claim 2 or 3
In the invention described above, the pressing means for pressing the guide member to the rotor side of the carriage is provided.

According to a fifth aspect of the present invention, in the fourth aspect of the invention, the pressing means includes a rotating member that contacts the guide member or a member equivalent to the guide member so as to face the movable member across the guide member, and the rotating member. A rotation control means is provided, which comprises a pressing member for pressing the member toward the guide member, and the rotation member of the pressing means is not rotatable when the carriage is moving forward and is rotatable when the carriage is moving backward.

According to the invention of claim 6, claim 1 or 5
In the invention described above, the outer peripheral length of the portion of the rotating member of the pressing means that is in contact with the guide member is set to be equal to the integral length of the moving distance from the start position of the carriage to the return position.

In the invention described in claim 7, claim 5 or 6
In the invention described above, the outer peripheral length of the portion of the rotor attached to the carriage that contacts the guide member and the outer peripheral length of the portion of the rotating member of the pressing unit that contacts the guide member or a member equivalent to this guide member are set equal. .

[0020]

According to the first aspect of the invention, in the reciprocating movement of the carriage, the carriage is slid at the time of the forward movement to perform stable driving with high accuracy, and is rotated at the time of the backward movement to be driven at a high speed. By doing so, high-precision and high-speed drive control is possible using a single drive motor, and it is possible to achieve a very simple configuration without using a high-speed, high-torque motor as in the past. Becomes

According to the second aspect of the present invention, the mover provided on the carriage is switched between sliding and rotating at every reciprocating movement, so that a highly accurate drive without load fluctuation due to sliding at the time of forward movement. It is possible to drive at high speed and low torque with a light load by rotation at the time of returning movement. Also, the outer peripheral length of the portion of the rotor in contact with the guide member is set to a fraction of the moving distance. As a result, the recess formed on the circumference of the rotor can be positioned at the sliding portion at the start position without fail, so that more accurate drive control can be performed and the carriage position accuracy can be improved. Become.

According to the third aspect of the invention, by making the outer peripheral lengths of the portions of at least two rotors in contact with the guide members equal, it is possible to prevent the positional deviation of the recesses at the start position due to the difference in the number of rotations of the rotors. This makes it possible to solve problems such as load fluctuations due to the positional deviation of the dents and to perform highly accurate drive control.

According to the fourth aspect of the present invention, the pressing means is used to bring the rotor into contact with the guide member at a constant pressure, so that high-precision driving can be stably performed during sliding. In addition, since the slippage between the rotor and the guide member at the time of rotation is eliminated, it is possible to reliably control the position of the recess.

According to the fifth aspect of the invention, like the rotor of the carriage, the rotary member of the pressing means is switched between sliding and rotating at every reciprocating movement, so that the rotary member causes the forward movement. It eliminates the problems of load fluctuations during operation and overloads during return movements, enabling even more precise drive control.
Moreover, the required torque can be made extremely small.

According to the sixth aspect of the invention, the outer peripheral length of the portion of the pressing member that contacts the guide member of the rotating member is set to a length that is an integral fraction of the moving distance. Can always be positioned at the sliding portion at the start position, which enables more highly accurate drive control.

According to the seventh aspect of the invention, by setting the outer peripheral length of the rotor on the carriage side and the outer peripheral length of the portion of the rotating member on the pressing means side in contact with the guide member to be equal, the number of rotations at the time of return is set. In the same manner, the recessed position of the rotor and the recessed position of the rotary member at the start position can be matched with each other with high accuracy, and more stable and highly accurate driving can be performed.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 will be described with reference to FIGS. First, before entering the description of the configuration of the main part of the present embodiment, the configuration of an image reading apparatus using a 1x sensor will be described with reference to FIG.

A contact glass 2 is provided on the upper part of the apparatus main body 1.
Is provided, and the original 3 is placed on the surface of the contact glass 2. A reading unit 4 for reading image information is provided in the apparatus body 1. The reading unit 4 includes a light source 5 for illumination, a rod lens array 6 that collects light that is illuminated by the light source 5 and reflected by the document 3.
The rod lens array 6 is composed of an equal-magnification sensor 7 which receives the light condensed and photoelectrically converts it. Such a reading unit 4 is mounted in the carriage 8.

With such a structure, when the document 3 is read, the carriage 8 is moved to a start position S at a constant speed.
To the direction A (sub-scanning direction), the reading scanning of the entire original 3 is performed in combination with the scanning in the main scanning direction by the equal-magnification sensor 7. Then, after the reading scanning is completed, the carriage 8 is moved back from the return position R in the B direction to the start position S, and a series of reading operations is completed. In such a series of reading operations, when the "forward movement" in the A direction greatly affects the read image quality, high precision drive is required, and in the "backward movement" in the B direction, the forward movement is required. Since it quickly returns to the start position S at a speed several times higher than that of (no drive precision is required), high speed and high torque drive is required. Therefore, in consideration of such a characteristic at the time of forward movement and a characteristic at the time of backward movement, the configuration described below is adopted.

Next, the structure of the reciprocating device for the carriage 8, which is the structure of the main part of this embodiment, will be described with reference to FIGS. In FIG. 1, a guide shaft 9 and a guide plate 10 as guide members are arranged along a side surface of the apparatus main body 1 parallel to the sub-scanning direction A. The guide shaft 9 is the left and right side plate 1
The guide plate 10 is fixed to the rear side plate 14 via the angle 13. A front side plate 15 is arranged on the guide shaft 9 side corresponding to the rear side plate 14. Further, on both bottom surfaces of the carriage 8, two V-shaped sliders are provided on the side of the guide shaft 9 with a certain distance therebetween.
A grooved bearing 16 is fixedly installed, and a slide piece 17 as a sliding type movable element is fixedly installed on the guide plate 10 side in the middle of the V grooved bearing 16. As a result, the carriage 8 is supported on the guide shaft 9 by the V-groove bearing 16 that regulates the movement in the main scanning direction, and is supported by the guide plate 10 by the slide piece 17 having a large degree of freedom, and the sub scanning direction (A, B). It is possible to reciprocate only in (direction).

The side surface of the carriage 8 on the guide shaft 9 side is located on the lower surface side opposite to the upper surface side of the guide shaft 9 in contact with the V-groove bearing 16 in order to regulate the vertical vibration of the carriage 8. Then, the pressing means 18 is attached. FIG. 2 shows a plan view of the pressing means 18. The pressing means 18 includes a roller 19 as a rotating member that contacts the lower outer peripheral surface of the guide shaft 9, and a pressing member 20 that presses the roller 19 toward the guide shaft 9. The pressing member 20 includes a rotary shaft 21 that rotatably supports the roller 19, an arm 22 to which the rotary shaft 21 is fixed, and a rotary shaft 2 that rotatably supports the arm 22.
3, a spring anchor 24 fixed to the side surface of the carriage 8, and a spring 25 having one end locked to the spring anchor 24 and the other end locked to the tip of the arm 22. As a result, the arm 22 is pulled upward by the spring 25 about the rotary shaft 23, and the roller 19 presses the guide shaft 9 downward from above.

Further, the roller 19 of the pressing means 18 is not rotatable when the carriage 8 is moving forward (direction A) and is rotatable when the carriage 8 is moving backward (direction B). A directional clutch 26 is provided.
The one-way clutch 26 is fitted on the rotary shaft 21 integrally with the roller 19. As a result, the one-way clutch 26 is mounted so as not to be rotatable in the clockwise direction and rotatable in the counterclockwise direction in FIG.

In such a structure, a drive mechanism (not shown) for reciprocating the carriage 8 along the guide shaft 9 and the guide plate 10 is provided in the apparatus body 1. Now, drive the carriage 8 to V by a drive mechanism (not shown).
Through the grooved bearing 16 and the slide piece 17, it is reciprocated along the guide shaft 9 and the guide plate 10 in the directions A and B. In this case, at the time of forward movement, the carriage 8 moves from the start position S to the return position R in the A direction, but since the clockwise force is applied to the one-way clutch 26, the roller 19 can rotate. Without being locked, the roller 19 advances while sliding on the guide shaft 9. Further, at the time of the backward movement, the return position R moves to the start position S in the B direction, but the one-way clutch 26 receives a counterclockwise force and is released from the locked state, so that the roller 19 rotates. This is possible, and the roller 19 advances while rotating on the guide shaft 9. Since such a principle of operation is the same as that of the pressing means 18 in which a sliding bearing without load fluctuation is used for the forward movement and a light bearing rotary bearing is used for the backward movement, It is possible to achieve both stable driving with high accuracy and high-speed low-torque driving.

As described above, in the reciprocating movement of the carriage 8, the carriage 8 is slid at the time of the forward movement so as to be driven with high precision and stable, and at the time of the backward movement, it is rotated without being slid to be driven at a high speed and a low torque. As a result, highly accurate and high speed drive control can be performed using one drive motor, and at the same time, a very simple structure is achieved without using a high speed and high torque motor as in the conventional case. be able to.

Next, claim 6 according to the invention of claim 1
The described invention will be described with reference to FIG. The description of the same parts as those in the first aspect of the present invention will be omitted, and the same reference numerals will be used for the same parts.

Here, the outer circumferential length of the roller 19 of the pressing means 18 is set to be equal to the length of an integral fraction of the moving distance of the carriage 8 from the start position S to the return position R. Therefore, the reason why the outer peripheral length of the roller 19 is set to such a condition will be described below.

FIG. 3 shows the shape of the roller 19 after the carriage 8 has been reciprocated several times. The material of the sliding member such as the roller 19 including the V-groove bearing 16 and the slide piece 17 is generally a guide member (guide shaft 9,
Considering scratches and noise on the guide plate 10), resin members are often used instead of metal members. Further, the cylindrical roller 19 is in point contact with the guide shaft 9 without making surface contact, and the roller 19 slides while being pressed against the guide shaft 9 during sliding. As a result, when the roller 19 is made of resin, a "dent 27" is generated at the contacted portion. The size and depth of the recess 27 are determined by the pressing pressure on the guide shaft 9 and the material and hardness of the roller 19, and the shape gradually becomes larger each time it slides from the initial state before starting, and fits in ( It will proceed to a certain size) and will not proceed thereafter, allowing stable sliding. If the position of the recess 27 formed at one place on the roller 19 is not controlled in this way, the position may change each time the roller slides, or countless different recesses may be formed on the circumference. As a result, it becomes a large factor of load fluctuation. Therefore, in this embodiment, the outer peripheral length of the roller 19 is set to a predetermined length in order to control the position of the recess 27 generated when the roller 19 is slid.

Therefore, a specific example in which the above-mentioned configuration conditions are set will be described. The diameter of the roller 19 is D, the start position S
L = nπD (1) where L is the distance from the return position to the return position R. However, each value is set so that the relational expression of n: integer is established. This (1)
If the formula is satisfied, the roller 19 rotates and returns an integer number of times when returning from the return position R to the start position S, so the circumferential position of the roller 19 that has returned to the start position S is at the return position R. The position can be the same as the position on the circumference. As a result, no matter how many times the carriage 8 is reciprocated and the sliding and rotation of the roller 19 is repeated, the recess 27 can always be positioned at the contact point (sliding portion) with the guide shaft 9. Therefore, by setting the outer peripheral length of the roller 19 of the pressing means 18 to a length which is an integral fraction of the moving distance in this way, the depression 27 generated on the rotation periphery of the roller 19 is always formed on the sliding portion at the start position S. It becomes possible to position it, and thereby more highly accurate drive control can be performed.

Next, an embodiment of the invention according to claim 2 and the invention according to claim 3 according to the invention according to claim 2 will be described with reference to FIG. The above-mentioned claim 1,
The description of the same parts as those in the invention described in 6 is omitted, and the same reference numerals are used for the same parts.

Here, in the reciprocating device used in the image reading apparatus of FIG. 6, at least one of the movers attached to the carriage 8 is formed by a rotor as shown in FIG. Rotation control means is provided on the child so that the carriage 8 cannot rotate when the carriage 8 moves forward and can rotate when the carriage 8 returns, and the outer peripheral length of the rotor is an integer of the moving distance from the start position S of the carriage 8 to the return position R. The length is set to be equal to one-half. Further, when there are a plurality of rotors, the outer peripheral lengths of at least two rotors are set to be equal.

Therefore, a specific example in which the above-mentioned configuration conditions are set will be described. As shown in FIGS. 4A and 4B, two rotary shafts 28 are mounted on both side surfaces of the carriage 8 at regular intervals, and a rotary shaft 29 is mounted at an intermediate position between the rotary shafts 28. There is. The rotary shaft 28 is provided with a rotary V-groove bearing 30 as a rotor (movable element), and the rotary shaft 29 is provided with a rotary type bearing 31 as a rotor (movable element) rotatably. As a result, the carriage 8 is supported by the guide shafts 9 and 32 as left and right guide members by the rotary V-groove bearing 30 that restricts the movement in the main scanning direction and the rotary bearing 31 that has a large degree of freedom.
It is reciprocally movable only in the sub-scanning direction.

A one-way clutch 33 as a rotation control means is integrally attached to the rotary V-groove bearing 30 and the rotary bearing 31 so as to fit with the rotary shafts 28 and 29. . This one-way clutch 33 is shown in FIG.
In (a), it is mounted so that it cannot rotate counterclockwise but can rotate clockwise.

In such a structure, the carriage 8 is reciprocated along the guide shafts 9 and 32 in the A and B directions by a drive motor (not shown). In this case, during the forward movement, the carriage 8 moves from the start position S to the return position R in the A direction, and the one-way clutch 33
Since a force in the counterclockwise direction is applied to the rotary type V-groove bearing 30 and the rotary type bearing 31, the rotary type V-groove bearing 30 and the rotary type bearing 31 move while sliding on the guide shafts 9 and 32. Further, at the time of the backward movement, the return position R is moved to the start position S in the B direction, the clockwise force is applied to the one-way clutch 33, and the one-way clutch 33 is released from the locked state.
The grooved bearing 30 and the rotary bearing 31 are rotatable, and travel on the guide shafts 9 and 32 while rotating with low torque.
Therefore, by switching between sliding and rotation at each forward movement and backward movement as described above, high-precision driving without load fluctuation at forward movement and high-speed low-torque driving at light load at backward movement are performed. be able to.

Further, the material of the rotary V-groove bearing 30 and the rotary bearing 31 used in this embodiment is metal considering the scratches and noises on the guide shafts 9 and 32 regardless of their shapes and sizes. Instead, resin materials are often used. Therefore, the depression 27 (see FIG. 3) is generated as in the case of the roller 19 as described in the invention of claim 6 described above. Therefore, in the present embodiment, the outer peripheral lengths of the rotary V-groove bearing 30 and the rotary bearing 31 are set to be equal to the integral fraction of the moving distance from the start position S to the return position R of the carriage 8. Set. Specifically, the guide shafts 9, 32
When the diameter of the rotary V-grooved bearing 30 abutting with is D ₁ , the diameter of the rotary bearing 31 is D ₂ , and the moving distance from the start position S to the return position R is L, the same as in (1) , L = n ₁ πD ₁ (2) = n ₂ πD ₂ (3) However, the respective values are set so that the relational expressions of n ₁ , n ₂ : integer are established. As a result, when returning from the return position R to the start position S, the rotary V-groove bearing 30 and the rotary bearing 31 respectively rotate and return an integral number of times, so that the position on the circumference at the time of the return is the circumference at the start. Can be matched with the position above. Therefore, because of this, even if the carriage 8 is reciprocated many times, the recess 27 is always kept in the guide shafts 9 and 3.
2 can be located at the contact portion.

Further, here, the two rotary V-groove bearings 30 which are arranged on the same guide shaft 9 at regular intervals, have the same diameter (D ₁ ) and the same outer peripheral length. Was set. The reason why the outer peripheral lengths are set to be the same in this way is that if the size (diameter) of the bearing is changed, no matter how small the outer peripheral length is an integer fraction of the moving distance, the number of rotations will change depending on the machining accuracy. This is because the positions of the recesses 27 at the start position become different from each other, and in particular, if such a position deviation occurs in the bearings on the same guide shaft 9, problems such as load fluctuations occur, and so on. This is because, when using a plurality of bearings, the diameters of the portions contacting the guide shaft 9 should be the same and the outer peripheral lengths should be the same, as much as possible. Further, by setting the diameter D ₂ of the rotary type bearing 31 to be the same as the diameter D ₁ of the rotary type V-grooved bearing 30 (D ₂ = D ₁ ), and by making the outer peripheral lengths equal and making the rotational speeds of the bearings equal, Three bearing recesses 27
Will always perform the same action, which results in the depression 27
Position control can be performed more reliably.

Next, one embodiment of the inventions of claims 4 and 5 according to the invention of claim 2 will be described with reference to FIG. The description of the same parts as those of the invention described in claims 1, 2, 3 and 6 is omitted, and the same reference numerals are used for the same parts.

Here, in the reciprocating device according to the second aspect of the invention as shown in FIG. 4, the guide shafts 9 and 32 are provided in the carriage 8 with the rotary V-groove bearing 30 and the rotary bearing 31.
A pressing means for pressing against is provided. The structure of the pressing means is not particularly limited, but as an example thereof, the pressing means 18 having the same structure as the structure described in the invention described in claim 1 (see FIG. 2) can be used. That is, FIG. 5 shows the structure of the pressing means 18, which is a roller 19 as a rotating member which is in contact with the surface of the guide shafts 9 and 32 in contact with the rotary V-groove bearing 30 and the rotary bearing 31. And this roller 19 to guide shafts 9, 3
It is composed of a pressing member 20 which is pressed to the 2 side. The detailed structure of the pressing member 20 here (similar to FIG. 2)
Is omitted. As a result, the rotary V-groove bearing 3
0, since the rotary bearing 31 and the guide shafts 9 and 32 are always in contact with each other at a constant pressure, high-precision driving during sliding can be stably driven, and there is no slipping during rotation. The position of the recess 27 can be controlled reliably.

However, when a rotating member such as a roller 19 is used as the pressing means 18, load fluctuation occurs, and when the roller 19 is a sliding member, overload occurs. Such load fluctuations and overloads may cause problems such as slippage. Therefore, in this embodiment, the rotation control means (one-way clutch 33) is added to the bearing side,
The roller 19 has a one-way clutch 26 as rotation control means.
Was added. That is, the one-way clutch 26 is integrally attached to the roller 19 and fitted to the rotary shaft 21. In FIG. 4, the one-way clutch 26 is mounted so as not to rotate in the clockwise direction but to rotate in the counterclockwise direction. Rotate when returning in the direction,
Thereby, the rotary V-groove bearing 30 and the rotary bearing 31
The same movement as in the case of the one-way clutch 33 is performed. Therefore, by providing such a one-way clutch 26, the problems of load fluctuation during forward movement and overload due to backward movement due to the roller 19 are eliminated, and high-precision driving during sliding is surely realized. In addition, the torque during rotation can be minimized.

Next, claim 6 according to the invention of claim 2
An embodiment of the described invention will be described. It should be noted that description of the same parts as those of the above-described inventions according to claims 1 to 5 is omitted, and the same reference numerals are used for the same parts.

Here, in the reciprocating device in which the pressing means 18 as shown in FIG. 5 is added to the invention of claim 2 as shown in FIG. 4, the outer peripheral length of the roller 19 constituting the pressing means 18 is The carriage 8 is set to have a length equal to an integral fraction of the moving distance from the start position S to the return position R. The reason for setting such conditions is that the rotary V-groove bearing 30 and the rotary bearing 31 provided on the carriage 8 as described in the invention of claim 6 according to the invention of claim 1 described above. Similarly to the case, when the roller 19 is used as the pressing means 18 and the roller is slid at the time of forward movement and rotated at the time of backward movement, the position of the recess 27 (see FIG. 3) generated on the circumference of the roller is not controlled, and the load fluctuations occur. This will cause

Specifically, the diameter of the roller 19 is D ₃ , the diameter of the rotary V-groove bearing 30 is D ₁ , the diameter of the rotary bearing 31 is D _2, and from the start position S to the return position R. Where L is the moving distance of L = n ₃ πD ₃ (4) = n ₁ πD ₁ (5) = n ₂ πD ₂ (6) where n ₁ , n ₂ , n _{3 are} integers. Set each value so that the relational expression holds. By satisfying such a relational expression, when the carriage 8 returns from the return position R to the start position S, the rotary V-groove bearing 30 and the rotary bearing 31 rotate by integers n ₁ and n ₂ , respectively. The roller 19 also returns by n ₃ rotations, and the circumferential position when returning to the start position S can be the same as the circumferential position at the return position R. Therefore, because of this, as with the rotary V-groove bearing 30 and the rotary bearing 31 described above, the recess 27 formed in the roller 19 at the return position is always positioned at the contact portion of the guide shafts 9 and 32. Therefore, it is possible to eliminate the problem of load fluctuation due to the recess 27 and to perform more highly accurate drive control.

Next, claim 7 according to the invention of claim 2
An embodiment of the described invention will be described. It should be noted that the description of the same parts as those of the invention described in claims 1 to 6 is omitted, and the same reference numerals are used for the same parts.

Here, in the reciprocating device in which the pressing means 18 as shown in FIG. 5 is added to the invention of claim 2 as shown in FIG. 4, the rotary type V-groove bearing 30 mounted on the carriage 8 The outer peripheral length of the portion of the die bearing 31 in contact with the guide shafts 9, 32 and the outer peripheral length of the portion of the roller 19 of the pressing means 18 in contact with the guide shafts 9, 32 are set to be equal.

In this way, the outer peripheral length of the bearing on the carriage 8 side and the outer peripheral length of the roller 19 are made to coincide, that is, the diameters D ₁ and D _{2 of} the rotary V-groove bearing 30 and the rotary bearing 31 and the roller 19 are made equal. If the outer circumferences are made equal to each other with D ₁ = D ₂ = D _{3 with} respect to the diameter D ₃ , the respective rotation speeds n ₁ , n ₂ , n ₃ are n.
_{Since 1} = n ₂ = n ₃ , the rotary V-groove bearing 30, the rotary bearing 31 and the recess 27 position of the roller 19 and the recess 27 of the roller 19 can be positioned on the same circumference. It is possible to further improve the positional accuracy of the recess 27 in S and always perform stable and highly accurate driving.

In the above-mentioned embodiments, the rotary V-groove bearing 30 and the rotary bearing 31 supporting the carriage 8 at three points have been described, but the supporting method is the drive system. The shape, the number of supporting points, the supporting position, etc. of the rotary movable element are not particularly limited because they greatly differ depending on the concept of the machine and the device. The shape, the number of pressing points, the pressing position, and the like are not limited on the side of the roller 19 serving as the rotating member. Also, the roller 19
Although the guide shafts 9 and 32 are pressed against the guide shafts 9 and 32, in addition to this, any member extending in the moving direction of the carriage 8 may be pressed against the roller 19 against the member. Further, the rotation type V-groove bearing 30, the rotation type bearing 31, and the rotation control means provided on the roller 19 include one-way clutches 26 and 3.
However, the present invention is not limited to this, and an electromagnetic clutch or another mechanism may be used as long as it is possible to switch between enabling and disabling rotation. Furthermore, the mover (rotary V-groove bearing 30, rotary bearing 31, roller 19) is also made of resin, but the material is not limited to this. Further, in the embodiment of the invention described in claim 1 (see FIG. 1), the pressing means 18 is provided only on one side with the guide shaft 9, but it may be provided on both side surfaces of the carriage 8 depending on the method of supporting and driving the carriage 8. You may Furthermore, although the cylindrical guide shafts 9 and 32 are used as the guide member, the guide member is not particularly limited to this shape.

Although the above embodiments have been described by taking the image reading device as an example, the present invention is not limited to this, and can be applied to all devices that reciprocate a carriage (moving body).

[0057]

According to the first aspect of the present invention, a carriage on which an optical member or the like is mounted, a movable element attached to the carriage, a movable element that is in contact with the movable element, supports the carriage, and moves in the reciprocating direction of the carriage. In a reciprocating device provided with a guide member that extends and guides forward and backward movements of the carriage, a rotary member that is in contact with a surface of the guide member that is opposite to a surface that is in contact with the movable element, and the rotary member A pressing means having a pressing member to be pressed against the guide member side is attached to the carriage, and rotation control means is provided for making the rotating member of the pressing means unrotatable when the carriage moves forward and rotatable when the carriage moves backward. Therefore, it is possible to perform high-precision and stable drive by sliding during forward movement and rotate it during backward movement. By driving at high speed and low torque, it is possible to perform high-precision and high-speed drive control using one drive motor, and a very simple configuration without using a high-speed, high-torque motor as in the past. Can be

According to a second aspect of the present invention, a carriage on which an optical member or the like is mounted, a movable element attached to the carriage, a movable element which is in contact with the movable element, supports the carriage, and extends in the reciprocating direction of the carriage. In the reciprocating device having a guide member for guiding the forward and backward movements of the carriage, at least one of the movers attached to the carriage is formed by a rotor, and Rotation control means is provided so as not to rotate when the carriage moves forward and to rotate when the carriage moves backward, and the outer peripheral length of the portion of the rotor that contacts the guide member is set to the movement distance from the start position to the return position of the carriage. Since it is set to be equal to the length of 1 / integer, high precision without load fluctuation due to sliding during forward movement It is possible to perform various types of driving, and at the time of returning movement, it is possible to perform high-speed and low-torque driving with a light load due to rotation.Also, the dent formed on the circumference of the rotor must be located on the sliding part at the start position. Therefore, the drive control can be performed with higher accuracy, and the positional accuracy of the carriage can be improved.

According to the invention of claim 3, in the invention of claim 2, the outer peripheral lengths of the portions of at least two rotors in contact with the guide member which are in contact with the guide member are set equal, so that the number of rotations of the rotor is increased. It is possible to prevent the position shift of the recess at the start position due to the difference of the above, and thereby to solve the problem of load fluctuation due to the position shift of the recess and to perform highly accurate drive control.

According to a fourth aspect of the present invention, in the second or third aspect of the present invention, since the pressing member for pressing the guide member against the rotor side of the carriage is provided, high precision driving during sliding is stably performed. Moreover, since the slippage between the rotor and the guide member at the time of rotation is eliminated, the position control of the recess can be surely performed.

According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the pressing member includes a rotating member that contacts the guide member or a member equivalent to the guide member so as to face the movable element while sandwiching the guide member. Since the rotation member is composed of a pressing member for pressing the rotating member toward the guide member side, the rotating member of the pressing means is not rotatable when the carriage is moving forward and is rotatable when the carriage is moving backward. By eliminating the problem of load fluctuation during forward movement due to members and overload during backward movement, more precise drive control can be performed, and the required torque can be made extremely small. is there.

According to a sixth aspect of the present invention, in the first or fifth aspect of the present invention, an outer peripheral length of a portion of the rotating member of the pressing means which is in contact with the guide member is an integer of a moving distance from a start position of the carriage to a return position. Since the length is set to be equal to one-half the length, the dent formed on the circumference of the rotating member can be always located at the sliding portion at the start position, which enables more highly accurate drive control. Is something that can be done.

According to a seventh aspect of the present invention, in the fifth or sixth aspect of the invention, the outer peripheral length of a portion of the rotor attached to the carriage that comes into contact with the guide member, and the guide member or the guide of the rotary member of the pressing means. Since the outer peripheral length of the part that is in contact with a member that is equivalent to the member is set to be the same, the number of rotations at the time of return can be the same, and the recessed position of the rotor at the start position and the recessed position of the rotating member can be accurately matched. Therefore, more stable and highly accurate driving can be performed.

[Brief description of drawings]

FIG. 1 (a) is a front view showing a configuration of a reciprocating device which is an embodiment of the invention described in claim 1, and FIG. 1 (b) is a side view thereof. Is.

FIG. 2 is a plan view showing the structure of a pressing unit.

FIG. 3A is a side sectional view of the roller, and FIG. 3B is a front sectional view of the roller.

FIG. 4 (a) is a front view showing the configuration of a reciprocating device according to an embodiment of the present invention, and FIG. 4 (b) is a side view thereof. Is.

FIG. 5 is a plan view showing the structure of a pressing unit.

FIG. 6 is a front view showing the configuration of the image reading apparatus.

[Explanation of symbols]

 8 Carriage 9,10 Guide member 16,17 Mover 18 Pressing means 19 Rotating member 20 Pressing member 26 Rotation control means 30,31 Rotor 32 Guide member 33 Rotation control means

Claims (7)

[Claims] 1. A carriage on which an optical member or the like is mounted, a movable element attached to the carriage, a movable element that is in contact with the movable element to support the carriage, and extends in the reciprocating direction of the carriage, and the forward movement of the carriage is performed. And a reciprocating device including a guide member for guiding the backward movement, a rotating member in contact with a surface of the guide member opposite to a surface in contact with the mover, and a pressing member for pressing the rotating member toward the guide member. Reciprocating movement, characterized in that the pressing means having the above is attached to the carriage, and the rotation member of the pressing means is not rotatable when the carriage is moving forward and is rotatable when the carriage is moving backward. apparatus. 2. A carriage on which an optical member or the like is mounted, a movable element mounted on the carriage, a movable element which is in contact with the movable element to support the carriage, and which extends in the reciprocating movement direction of the carriage and is a forward movement of the carriage. And a guide member for guiding the backward movement, at least one of the movers attached to the carriage is formed by a rotor, and the rotor rotates when the carriage moves forward. Rotation control means for disabling the rotation of the carriage when the carriage is moved back is provided, and the outer peripheral length of a portion of the rotor that is in contact with the guide member is an integral fraction of the moving distance from the start position to the return position of the carriage. A reciprocating device characterized by being set to be equal to the height. 3. The reciprocating device according to claim 2, wherein the outer peripheral lengths of the portions of at least two rotors that come into contact with the guide member and that come into contact with the guide member are set equal. 4. The reciprocating device according to claim 2, further comprising a pressing means for pressing the guide member to the rotor side of the carriage. 5. The pressing means comprises a rotating member that contacts the guide member or a member equivalent to the guide member so as to face the mover while sandwiching the guide member, and a pressing member that presses the rotating member toward the guide member. 5. The reciprocating device according to claim 4, further comprising rotation control means for making the rotating member of the pressing means unrotatable when the carriage moves forward and rotatable when the carriage returns. 6. The outer peripheral length of a portion of the rotating member of the pressing means that is in contact with the guide member is set to be equal to the length of an integral fraction of the moving distance from the carriage start position to the return position. The reciprocating device according to claim 1 or 5. 7. An outer peripheral length of a portion of the rotor attached to the carriage that contacts the guide member and an outer peripheral length of a portion of the rotating member of the pressing unit that contacts the guide member or a member equivalent to the guide member are set to be equal. The reciprocating device according to claim 5, wherein: