JP3436555B2 - Reciprocating device - Google Patents

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]

[0014]

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 that includes a guide member that extends in the reciprocating direction and guides forward and backward movements of the carriage, at least one of the movers attached to the carriage is formed by a rotor. The rotor is provided with rotation control means that cannot rotate when the carriage moves forward and can rotate when the carriage returns, and returns the outer peripheral length of a portion of the rotor that contacts the guide member from the start position of the carriage. It was set so as to be equal to the integral length of the moving distance to the position.

[0015] In the present invention of claim 2, wherein, in the invention according to the first aspect, and set equal to the outer peripheral length of the portion in contact with the guide member in at least two rotor contacts the guide member.

According to the invention of claim 3 , claim 1 or 2
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 fourth aspect of the present invention, in the third aspect of the present invention, the pressing means includes a rotating member that comes into contact with the guide member or a member equivalent to the guide member so as to face the movable element while sandwiching 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 a fifth aspect of the present invention, in the fourth aspect of the invention, the outer peripheral length of the portion of the pressing member that is in contact with the guide member of the rotating member is an integral amount of the moving distance from the carriage start position to the return position. It was set to be equal to the length of 1.

According to the invention of claim 6 , claim 4 or 5
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]

[0021]

According to the first 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 perform high-speed, low-torque driving with a light load due to rotation when returning.
Since the outer peripheral length of the portion of the rotor that is in contact with the guide member is set to be an integral fraction of the moving distance, the recess formed on the periphery of the rotor can be located at the sliding portion at the start position. The drive control can be performed with higher accuracy, and the positional accuracy of the carriage can be improved.

According to the second aspect of the present invention, by making the outer peripheral lengths of the portions of the 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 third aspect of the present invention, by using the pressing means to bring the rotor into contact with the guide member at a constant pressure, it is possible to stably perform high precision driving 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 fourth 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, whereby the forward movement due to the rotary member is caused. 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 invention of claim 5 , the outer peripheral length of the portion of the rotating member of the pressing means which is in contact with the guide member is set to be 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 sixth aspect of the present invention, 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 which is in contact with the guide member are set equal to each other, so that 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 present invention 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, another embodiment will be described with reference to FIG. The description of the same parts as those in the above-described embodiment 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 it slides, or innumerable different recesses may occur 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
When the distance from the return position to the return position R is L, L = nπD (1) However, each value is set so that the relational expression of n: integer holds. 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, another embodiment will be described with reference to FIG. The description of the same parts as those in the above-described embodiment will be omitted, and the same reference numerals will be 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, each value is set so that the relational expressions of n ₁ and n ₂ : integers 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, another embodiment will be described with reference to FIG. The description of the same parts as those in the above-described embodiment will be omitted, and the same reference numerals will be used for the same parts.

Here, in the reciprocating device according to the first aspect of the present 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 of the above-described embodiment (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 a pressing member 20 for pressing the roller 19 against the guide shafts 9 and 32. The pressing member 20 here
The detailed description of the configuration (similar to FIG. 2) is omitted. As a result, the rotary V-groove bearing 30, the rotary bearing 31, and the guide shafts 9 and 32 are always in contact with each other at a constant pressure, so that high-precision driving during sliding can be stably driven. Moreover, since there is no slippage during rotation, it is possible to reliably control the position of the recess 27.

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, another embodiment will be described. The description of the same parts as those in the above-described embodiment will be omitted, and the same reference numerals will be used for the same parts.

[0050] Here, the reciprocating device obtained by adding a pressing means 18 as shown in FIG. 5 to the first aspect of the present invention as shown in FIG. 4, the circumferential length of the roller 19 constituting the pressing means 18, 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 a condition, a rotary V grooved bearing 30 provided on the carriage 8 that looks as though it was described above, as in the case of rotary bearings 31, upon forward movement with roller 19 to the pressing means 18 This is because if the position of the recess 27 (see FIG. 3) generated on the circumference of the roller surface is not controlled when sliding and rotating at the time of returning movement, load fluctuation will be caused.

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 = 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, another embodiment will be described. The description of the same parts as those in the above-described embodiment will be omitted, and the same reference numerals will be used for the same parts.

[0053] Here, the reciprocating device obtained by adding a pressing means 18 as shown in FIG. 5 to the first aspect of the present invention as shown in FIG. 4, a rotary V grooved bearing 30 mounted on the carriage 8, the rotation 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. In the embodiment of FIG. 1 (see FIG. 1), the pressing means 1
Although 8 is provided only on one side where the guide shaft 9 is provided, it may be provided on both side surfaces of the carriage depending on the method of supporting and driving the carriage 8. 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]

[0058]

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 including a guide member that extends and guides forward and backward movements of the carriage, at least one of the movers attached to the carriage is formed by a rotor, and the rotor is provided. Is provided with rotation control means that cannot rotate when the carriage is moving forward and can be rotated when the carriage is moving backward, and moves the outer peripheral length of the portion of the rotor that contacts the guide member from the start position to the return position of the carriage. Since it is set to be equal to the integral length of the distance, it is possible to avoid high load fluctuation due to sliding during forward movement. Degree drive is performed, can perform driving of the light load, high-speed low-torque due to the rotation time of the backward movement,
In addition, since the recess formed on the circumference of the rotor can be always located at the sliding portion at the start position, the drive control can be performed with higher accuracy, and the position accuracy of the carriage can be improved. is there.

According to a second aspect of the present invention, in the first aspect of the invention, the outer peripheral lengths of the portions of the at least two rotors in contact with the guide member which are in contact with the guide member are set to be equal. 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 third aspect of the present invention, in the first or second aspect of the present invention, since the pressing means for pressing the guide member against the rotor side of the carriage is provided, high precision drive 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 fourth aspect of the present invention, in the third aspect of the present invention, the pressing means includes a rotating member which is in contact with 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 fifth aspect of the present invention, in the invention according to the fourth aspect , the outer peripheral length of a portion of the pressing member that is in contact with the guide member is an integral part of the moving distance from the carriage start position to the return position. Since the length is set to be equal to 1, the recess 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. It is a thing.

According to a sixth aspect of the present invention, in the fourth or fifth 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. 1A is a front view showing a configuration of a reciprocating device which is an embodiment of the present invention, and FIG. 1B 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. 4A is a front view showing a configuration of a reciprocating device which is another embodiment, and FIG. 4B 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 (6)

(57) [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 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. 2. A guide member contact at least two reciprocating apparatus according to claim 1, wherein the set equal circumferential length of a portion in contact with the guide member in the rotor. Wherein the guide member reciprocates apparatus according to claim 1 or <br/> 2 wherein in that a pressing means for pressing the rotor side of the carriage. 4. The pressing means comprises a rotating member that contacts the guide member or a member equivalent to this 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. 4. The reciprocating device according to claim 3 , 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. 5. The outer peripheral length of a portion of the rotating member of the pressing means which is in contact with the guide member is set to be equal to the integral length of the moving distance from the carriage start position to the return position. The reciprocating device according to claim 4 . 6. The outer peripheral length of a portion of the rotor attached to the carriage that contacts the guide member and the 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 equal. The reciprocating device according to claim 4 or 5 , characterized in that: