JP2011223189A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading device which enables easy fixing operation of its carriage and prevents forgetting to lock or unlock it.SOLUTION: The image reading device comprises a reading unit 12, a carriage 13, and a moving mechanism 14. One stroke end of the sub-scanning direction is used as a fixing position where a carriage fixing mechanism is installed. The carriage fixing mechanism comprises a locked part 41 installed at the carriage 13, a lock body 40 held by a document mounting table, and a spring 42 energizing the lock body 40. The lock body 40 comprises a passive part 48 which relays the movement of the carriage 13, and a lock part 47 which comes into contact with the locked part 41 according to the position change of the passive part 48. In a state where the carriage 13 is located at the fixing position, the lock part 47 comes into contact with the locked part 41 to lock the carriage 13 so that it cannot be moved.

Description

  The present invention relates to an image reading apparatus applied to a copying machine, a scanner, a facsimile, and the like, and more particularly to a technique for preventing a carriage from being damaged during transportation.

2. Description of the Related Art Conventionally, there has been known an image reading apparatus including a carriage damage prevention mechanism for preventing carriage damage during transportation. For example, in the image forming apparatus disclosed in Patent Document 1, a carriage fixing screw is screwed into a carriage from a screw hole provided in a bottom plate, and the carriage is pressed against a platen glass, thereby suppressing vibration in the vertical direction of the carriage. Prevents damage.
Similar manual carriage damage prevention mechanisms are also disclosed in Patent Documents 2 to 4. In these Patent Documents 2 to 4, the carriage is fixed when a user operates a lock lever provided outside the housing of the image reading apparatus.

Japanese Patent Laying-Open No. 2003-075932 (paragraph number 0053, FIG. 4) Japanese Patent Laying-Open No. 2008-092373 (paragraph number 0043, FIG. 10) JP 2008-211281 A (paragraph number 0077, FIGS. 4 and 5) Japanese Patent Application Laid-Open No. 07-219067 (paragraph number 0046, FIGS. 1 and 2)

  In the structure in which the carriage is prevented from moving by manually operating the lock lever or screwing the lock screw as in Patent Documents 1 to 4, the entire carriage fixing operation is left to the user. Therefore, there is a risk that the user forgets the fixing work during transportation and the carriage is inadvertently damaged. Further, the user may forget to perform the unlocking operation after transportation, and the carriage or the carriage driving mechanism may be damaged. Furthermore, when the carriage is fixed, two operations, that is, an operation for moving the carriage to a predetermined position and a lock operation for fixing the carriage are required, which is disadvantageous in that the series of fixing operations is troublesome.

The present invention has been made in view of the above circumstances, and one of its main purposes is that it is possible to easily perform a fixing operation of the carriage, and an image in which it is difficult to forget to lock or unlock. To provide a reader.
An object of the present invention is to provide an image reading apparatus capable of locking and unlocking a carriage with one touch.

  An image forming apparatus according to the present invention includes a document placing table including a platen glass 11, a reading unit 12 that is disposed inside the document placing table and reads a document placed on the platen glass 11, and a reading unit 12. A carriage 13 is provided. Furthermore, a moving mechanism 14 for moving the carriage 13 in the sub-scanning direction is provided. At least one stroke end in the sub-scanning direction of the document placing table is set as a restraining position, and a carriage fixing mechanism for restraining the carriage 13 so as not to move is provided at this position. The carriage fixing mechanism can automatically lock the carriage 13 in conjunction with the movement of the carriage 13 toward the restraining position, and can automatically unlock the carriage 13 in conjunction with the movement of the carriage 13 away from the restraining position. Characterized by points.

  The carriage fixing mechanism includes a locked portion 41 provided on the carriage 13, a lock body 40 supported by the frame 29 of the document table, and a spring 42 that biases the lock body 40 toward the lock release position. ing. The lock body 40 is supported by the frame 29 of the document table so that the lock body 40 can be displaced between a lock position where the lock body 41 abuts on the locked portion 41 and a lock release position separated from the locked portion 41. The lock body 40 includes a passive portion 48 that inherits the movement of the carriage 13 toward or away from the restraining position, and a lock portion 47 that contacts or separates from the locked portion 41 in conjunction with the displacement of the passive portion 48. . In a state where the carriage 13 is located at the restraining position, the lock portion 47 contacts the locked portion 41 and locks the carriage 13 so as not to move.

  The lock body 40 is supported by the frame 29 of the document table so that it can slide back and forth between the lock position and the lock release position. On the peripheral wall of the carriage 13 facing the locked portion 41, an entrance 54 for allowing the lock portion 47 to enter and exit and an operation portion 44 for operating the passive portion 48 are provided. Each of the passive portion 48 and the operation portion 44 is provided with cam surfaces 55 and 56 for converting the movement of the carriage 13 into a sliding operation in the locking direction of the lock body 40. In the process in which the carriage 13 approaches the restraint position, the lock portion 47 enters the entrance 54 and faces the locked portion 41. Further, in a state where the carriage 13 is located at the restraining position, the joint surfaces 57 and 58 of the lock portion 47 and the locked portion 41 come into contact with each other to lock the carriage 13 so as not to move.

  The lock body 40 includes a swing arm 65 that is swingably supported by the frame 29 of the document table, a passive portion 48 provided at one end of the swing arm 65, and a hook shape provided at the other end of the swing arm 65. An entrance 54 that allows the lock portion 47 to enter and exit is provided on the peripheral wall of the carriage 13 that faces the locked portion 41. In the process in which the carriage 13 approaches the restraining position, the passive portion 48 is pushed by the peripheral wall of the carriage 13 so that the lock portion 47 and the locked portion 41 that have entered the entrance 54 face each other. Further, in a state where the carriage 13 is positioned at the restraining position, the lock portion 47 is hooked on the locked portion 41 and locks the carriage 13 so as not to move.

  An operation tool 62 that activates the moving mechanism 14 is disposed on the operation panel 7. In a state where the operation tool 62 is switched to the on state, the carriage 13 is moved to the restraining position by the moving mechanism 14 and is locked so as not to be moved by the carriage fixing mechanism.

  A contact glass 15 is disposed adjacent to the platen glass 11. An automatic document feeder 6 that feeds a document toward the upper surface of the contact glass 15 is provided on the platen cover 5. The document reading position where the carriage 13 is positioned below the contact glass 15 is made to coincide with the restraining position. The carriage 13 located at the document reading position is fixed by a carriage fixing mechanism.

  In the image reading apparatus according to the present invention, the carriage is automatically locked by the carriage fixing mechanism when the carriage is moved by the moving mechanism to the restraining position provided at at least one stroke end in the sub-scanning direction. . As described above, when the carriage is automatically locked by the carriage fixing mechanism at the restraining position, it is possible to greatly reduce the burden on the user of the carriage fixing work or the burden on the operator during transportation. In other words, in the present invention, there is no need to manually lock the screws and levers, and the lock can be fixed simply by moving the carriage to the restraining position with the moving mechanism, thus greatly increasing the work load on the user or operator. Can be reduced. In addition, since the carriage can be locked by a simple operation by driving the moving mechanism and moving the carriage to the restraining position at the end in the sub-scanning direction, it is difficult to forget to lock during transportation and reliability Can be obtained.

  In the present invention, the carriage restraint by the carriage fixing mechanism can be automatically released simply by activating the moving mechanism and moving the carriage. Therefore, after transportation, the user or the like can perform the unlocking operation such as removing the lock screw. There is no need to do. Therefore, there is no room for forgetting to lock, and an image reading apparatus with excellent reliability can be obtained.

  In the present invention, the carriage fixing mechanism is constituted by a locked portion provided on the carriage side, a lock body provided on the document support base side, and a spring for biasing the lock body toward the unlocking position. The lock body is composed of a passive part that takes over the movement of the carriage toward and away from it, and a lock part that contacts or separates from the locked part in conjunction with the displacement of the passive part. According to the carriage fixing mechanism configured as described above, the carriage can be locked so as to be immovable by switching the lock body to the locking posture only by moving the carriage toward the restraining position by the moving mechanism. Further, the carriage can be unlocked by moving the locked carriage in a direction away from the restraining position and displacing the lock portion to the unlocking posture with the spring.

  As described above, in the present invention, the carriage is automatically locked or unlocked by the carriage fixing mechanism by utilizing the operation when the carriage is moved by the moving mechanism. Therefore, it is not necessary to use a dedicated actuator or the like for driving the carriage fixing mechanism, and an increase in the manufacturing cost of the image reading apparatus due to the provision of the carriage fixing mechanism can be suppressed. Also, since the locked portion is provided on the carriage and only the lock body is provided on the document table, it is not necessary to secure a new installation space for the carriage fixing mechanism in the document table, and the carriage fixing mechanism can be easily added. can do. The degree of freedom in designing the image reading apparatus is not impaired. Further, since the lock body is urged to the unlock position by the spring, the lock portion can be automatically returned to the lock release position when the carriage is separated from the lock body. It is possible to improve the reliability of operation by accurately switching.

  In the carriage fixing mechanism including the lock body that reciprocates and the cam surface for converting the operation, the operation in which the carriage approaches the restraint position is converted into the lock operation on the cam surface, and the lock body is displaced to the lock position. Lock the carriage so that it cannot move with a lock. Specifically, as shown in FIG. 7, using the operation of the carriage approaching the restraining position, the lock portion is caused to enter the entrance and face the locked portion. Further, the cam surface of the operation unit abuts against the cam surface of the passive unit, and the lock body is displaced to the lock position against the urging force of the spring, and finally the joint surfaces of the lock unit and the locked unit are contacted. (See FIG. 1).

  As described above, when the locked portion is captured by the reciprocatingly locking lock body, the carriage is displaced to the restraining position, and the joining surface of the locked portion and the locked portion is brought into contact as shown in FIG. Can be locked so that it cannot move in the forward / backward, left / right and up / down directions at the restraint position. Therefore, in a state where the carriage is locked by the carriage fixing mechanism, the carriage can be firmly held by the lock body and can be continuously fixed to the restraining position even when receiving an external force or an impact from the outside. Further, at the same time when the carriage starts to move away from the lock body, the joint surface of the lock portion begins to separate from the joint surface of the locked portion, and the restraint of the carriage by the lock body can be quickly released. With the addition of the carriage fixing mechanism, it is also advantageous in that it is not necessary to change the structure of the moving mechanism or change the driving form.

  In a carriage fixing mechanism that forms a lock body with a swing arm, a passive portion provided at one end and the other end of the swing arm, and a hook-shaped lock portion, the operation of the carriage is converted into a swing operation, and the lock portion Is locked to the locked part so that the carriage cannot be moved. Thus, according to the carriage fixing mechanism that captures and fixes the locked portion with the swinging lock body, the hook-shaped lock portion is brought into contact with the joint surface of the locked portion as shown in FIG. Can be locked in a restrained position so that it cannot move. Therefore, in a state where the carriage is locked by the carriage fixing mechanism, the carriage can be firmly held by the lock body and can be continuously fixed to the restraining position even when receiving an external force or an impact from the outside. Further, at the same time when the carriage starts to move away from the lock body, the joint surface of the lock portion begins to separate from the joint surface of the locked portion, and the restraint of the carriage by the lock body can be quickly released.

  If an operation tool for activating the moving mechanism is arranged on the operation panel, the carriage can be forcibly moved to the restraining position and locked by the lock body simply by switching the operation tool to the on state. The operation tool is formed in, for example, a push button shape or a slide knob shape, and can be switched with one touch, so that the carriage can be easily fixed with a lock body with a very simple effort.

  If the document reading position of the carriage on the contact lens side coincides with the restraining position of the carriage, the carriage can be fixed by the lock body of the carriage fixing mechanism only by positioning the carriage at the document reading position. According to this, since the carriage can be prevented from inadvertently moving up and down or moving in the sub-scanning direction at the document reading position, it is possible to prevent a reading defect from occurring during the automatic document reading operation, and Can be read more appropriately. The user or operator does not need to be aware of locking or unlocking the carriage when transporting the image reading device, and merely places the carriage at the previous document reading position.

It is a cross-sectional top view which shows the carriage fixing mechanism which concerns on this invention. 1 is a front view conceptually showing an image reading apparatus. It is a longitudinal front view showing a carriage and an automatic document feeder. It is a top view which shows a carriage, a carriage fixing mechanism, etc. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is a cross-sectional plan view which shows the state in the middle of the displacement of a lock body to a lock position. It is a cross-sectional top view of the carriage fixing mechanism which concerns on another Example. It is CC sectional view taken on the line in FIG. It is a cross-sectional top view which shows the lock body of a lock release state. It is a vertical side view which shows another Example of a lock part and a to-be-locked part.

(Embodiment) FIGS. 1 to 6 show an embodiment in which the image reading apparatus according to the present invention is applied to a multifunction machine having a copy function and a facsimile function. In the present invention, “front / rear”, “left / right”, and “up / down” follow the cross arrows shown in FIGS.

  In FIG. 2, the multifunction machine includes a recording unit 1 and an image reading unit 2 disposed on the upper side of the recording unit 1. The recording unit 1 includes an image recording device 3 and a fixing device 4. A platen cover 5 for opening and closing the document reading surface is provided on the upper surface of the image reading unit (image reading device) 2, and an ADF (automatic document feeder) 6 is incorporated in the upper part thereof. An operation panel 7 is provided on the front surface of the image reading unit 2, and a paper feed cassette 8 is disposed below the recording unit 1. The paper on which the image is printed via the image recording device 3 and the fixing device 4 is discharged to the paper discharge unit 9 below the image reading unit 2. The platen cover 5 can swing up and down around a hinge (not shown) provided at the rear end thereof, and can change its posture between a state where it covers the upper surface of the document table and a state where the upper surface of the document table is opened. .

  In FIG. 3, the upper surface of the document placing table is covered with a platen glass 11, inside which is a reading unit 12 for reading the document, a carriage 13 for supporting the reading unit 12, and a movement for moving the carriage 13 in the sub-scanning direction. A mechanism 14 and the like are arranged. A contact glass 15 is disposed adjacent to the platen glass 11. The reading unit 12 includes a light source 17, first to fourth mirrors 18 to 21, an image sensor (CCD) 22, and the like.

  When reading a fixed document placed on the upper surface of the platen glass 11, the state in which the reading unit 12 is positioned below the left edge of the platen glass 11 is set as a scanning start position, and the reading unit 12 is moved by the carriage 13 in FIG. The original is scanned by moving it to the right. This scanning direction is defined as a sub scanning direction. In a state where the reading unit 12 is positioned at the original reading position directly below the contact glass 15 on the left side from the previous scanning start position, an image of the original conveyed along the upper surface of the contact glass 15 by the ADF 6 is read. Can be read with.

  The carriage 13 is formed of a hollow box, a pair of left and right slide blocks 25 provided at the rear end thereof are slidably guided by a guide shaft 26, and a slider 27 provided on the lower surface of the front end of the carriage 13 is a guide rail 28. It is guided to slide freely. As shown in FIG. 4, the guide shaft 26 and the guide rail 28 are respectively fixed between the left and right side walls of the frame 29 of the document table.

  The moving mechanism 14 includes a motor 32, a driving pulley 33 driven by the motor 32, a driven pulley 34, an endless belt 35 wound around these pulleys 33 and 34, and the like. The members 32 to 35 constituting the moving mechanism 14 are arranged in a space between the guide shaft 26 and the rear wall of the frame 29. The motor 32 and the driving pulley 33 are arranged near the end of the scanning stroke of the carriage 13 (near the right end in FIG. 4), and the driven pulley 34 is near the scanning start position of the scanning stroke of the carriage 13 (near the left end in FIG. 4). ). The carriage 13 is connected to the linear portion on the upper side of the belt 35 via a connecting arm 36 fixed to the rear surface near the start end of the scanning stroke, whereby the carriage 13 reciprocates between the pulleys 33 and 34. it can.

  In order to prevent the carriage 13 from moving due to an external force when shipping the image reading apparatus from the factory or transporting the temporarily stored image reading apparatus to the end user's office, Carriage fixing mechanisms are provided at both ends of the carriage 13 in the sub-scanning direction. Specifically, each of the stroke ends of the carriage 13 in the sub-scanning direction is set as a restricting position, and a carriage fixing mechanism is provided at both the restricting positions. In FIG. 4, the restraining position on the left end side of the carriage 13 in the sub-scanning direction coincides with the state where the reading unit 12 is located at the document reading position directly below the contact glass 15. Further, the restraining position on the right end side of the carriage 13 in the sub-scanning direction coincides with the state in which the reading unit 12 is positioned at the right end of the sub-scanning stroke.

  The carriage fixing mechanism includes a lock body 40, a locked portion 41 fixed by the lock body 40, a spring 42 that urges the lock body 40 toward the unlocking position, a guide base 43 that supports the lock body 40, And an operation unit 44 for displacing the lock body 40. The lock body 40 is made of a flat plastic molded product, and upper and lower sides thereof are supported by a pair of upper and lower guide grooves 46 provided in the guide base 43 so as to be slidable back and forth (see FIG. 3). An L-shaped lock portion 47 for locking and fixing the locked portion 41 is integrally formed at the rear portion of the lock body 40. In addition, a passive hole (passive) portion 48 that inherits the movement of the carriage 13 toward or away from the restraining position and a spring receiving piece 49 are formed at the front portion of the lock body 40 in correspondence with the previous operation portion 44. It is.

  The lock portion 47 contacts or separates from the locked portion 41 in conjunction with the passive hole 48 being displaced by the operation portion 44. The spring 42 is incorporated between a spring receiving piece 49 and a spring receiving body 50 provided in the front and rear halfway portion of the guide base 43. The guide base 43 is fastened with screws to the inner surfaces of the left and right walls of the frame 29 described above. The lock body 40 has a lock position in the rear (the state shown in FIG. 1) in which the lock portion 47 abuts on the locked portion 41, and a front lock in which the lock portion 47 is pushed back by the spring 42 and separated from the locked portion 41. It can be slid back and forth between the release position (state shown in FIG. 6). The front end of the lock body 40 at the unlocking position is received by a stopper wall 51 provided on the guide base 43.

  The locked portion 41 and the operation portion 44 are formed as projections on the inside and outside of the left and right side walls of the carriage 13 facing the lock body 40, respectively, and there is an entrance 54 that allows the lock portion 47 to enter and exit between them. It is open. The locked portion 41 is continuous with the rear edge of the entrance 54 and protrudes inward of the carriage 13. In addition, the operation unit 44 protrudes outward of the carriage 13 continuously from the front edge of the entrance 54. In a state where the lock body 40 is located at the unlock position, the lock portion 47 and the entrance 54 face each other right and left. Therefore, in a state where the carriage 13 is close to the lock body 40, as shown in FIG. 7, the lock portion 47 relatively enters the inside of the entrance 54 and faces the locked portion 41 in the front-rear direction.

  The lock body 40 is switched from the lock release position to the lock position while countering the urging force of the spring 42 using, for example, an operation when the carriage 13 moves toward the left restraint position. Alternatively, in conjunction with the operation when the carriage 13 moves toward the right restraint position, the urging force of the spring 42 switches the lock position to the unlock position. In order to perform this switching operation more smoothly, cam surfaces 55 and 56 formed of inclined surfaces are formed in parallel on the rear surface of the operation portion 44 and the rear edge of the passive hole 48, respectively. Further, on the front surface of the locked portion 41 and the rear surface of the lock portion 47, joint surfaces 57 and 58, which are inclined surfaces that are joined in surface contact with each other, are formed in parallel.

  An operation window 61 that is opened and closed by a cover 60 is opened in the operation panel 7, and a push button (operation tool) 62 that activates the moving mechanism 14 is disposed inside the operation window 61. When the push button 62 is pushed in and switched to the on state, the carriage 13 is forcibly moved to the left restraint position by the moving mechanism 14 and is locked so as not to be moved by the carriage fixing mechanism.

  As described above, according to the image reading apparatus provided with the carriage fixing mechanism at both ends in the sub-scanning direction, the carriage 13 can be automatically locked in conjunction with the operation of the carriage 13 approaching the restraining position. Further, the carriage 13 can be automatically unlocked in conjunction with the movement of the carriage 13 away from the restraining position. Hereinafter, the details of the locking operation and the unlocking operation of the carriage 13 by the carriage fixing mechanism will be described. However, the operation of the left and right carriage fixing mechanisms is only reversed in the left and right directions. Will be described.

  As shown in FIG. 6, in a state where the carriage 13 is away from the restraining position, the lock body 40 is pushed by the spring 42 and held at the unlocked position. In this state, when the push button 62 is turned on, the motor 32 of the moving mechanism 14 is activated to move the carriage 13 toward the left restraint position. As the carriage 13 moves, as shown in FIG. 7, the operation portion 44 enters the passive hole 48, and at the same time, the lock portion 47 relatively enters the carriage 13 from the entrance 54.

  After the cam surface 55 of the operating portion 44 contacts the cam surface 56 of the passive hole 48, the movement operation of the carriage 13 is converted into a backward locking operation by both cam surfaces 55 and 56. Therefore, the lock body 40 slides backward toward the lock position against the urging force of the spring 42, and the lock portion 47 slides further inward of the entrance 54 during that time. Then, in a state where the carriage 13 has moved to the restraint position, the lock body 40 is switched to the locked posture, and the joining surface 58 of the lock portion 47 and the joining surface 57 of the locked portion 41 are joined in a surface contact manner. That is, the carriage 13 is locked by the lock body 40 so as not to move. In this locked state, even if an impact force or a movement inertial force is applied to the carriage 13 during transportation, the carriage 13 does not move freely and is kept in the restrained position. Accordingly, it is possible to prevent the optical system structure of the reading unit 12 from being distorted or the carriage 13 from running away and damaging the mirror system.

  As described above, in many cases, the carriage 13 is moved to the restraining position on the contact glass 15 side and locked by the lock body 40. However, the carriage 13 is moved to the restraining position on the end side in the sub-scanning direction to lock the locking body 40. It can also be locked with. For example, the carriage 13 at the time of shipment from the factory can be locked at the restricting position on the end side in the sub-scanning direction, and the carriage 13 when the end user transports the image reading apparatus can be locked at the restricting position on the contact glass 15 side. .

  When the image reading apparatus after transportation is installed at a predetermined position and the main power supply is turned on, for example, in the copy mode, when the start button is turned on with the document placed on the upper surface of the platen glass 11, the carriage 13 Moves from the left restraint position to the scan start position. When the carriage 13 moves from the restraint position to the scanning start position, the contact positions of both the cam surfaces 55 and 56 are displaced by the amount that the operation unit 44 is separated from the lock body 40. In detail, the contact position of the cam surface 55 of the operation unit 44 gradually moves away from the entrance 54, and at the same time, the lock body 40 is pushed by the spring 42 and slides forward in the unlocking direction.

  When the cam surfaces 55 and 56 begin to separate, the joint surfaces 57 and 58 of the lock portion 47 and the locked portion 41 are completely separated as shown in FIG. Switching to the unlocked state, the front end is received by the stopper wall 51. Thereafter, the carriage 13 moves in the scanning direction through the scanning start position. In the copy mode, the carriage 13 for reading the document conveyed by the ADF 6 is still locked at the restraining position, but when the mode is switched to the mode for reading the document placed on the upper surface of the platen glass 11, the carriage 13 In the same manner, the lock by the lock body 40 can be automatically released.

  According to the image reading apparatus having the carriage fixing mechanism having the above-described configuration, when necessary, the carriage 13 can be moved to the restraining position and locked by the carriage fixing mechanism simply by turning on the push button 62. Furthermore, the carriage 13 can be moved in the scanning direction simply by turning on the start button provided on the operation panel 7, and the locked state by the carriage fixing mechanism can be released. Therefore, the carriage 13 can be easily fixed as compared with the conventional carriage fixing structure of this type, and the forgetting to lock or unlock the carriage 13 can be solved.

  8 and 10 show another embodiment of the lock body 40. There, a swing arm 65 supported swingably by a guide base 43, a passive portion 48 provided at the rear end of the swing arm 65, a hook-like lock portion 47 provided at the front end of the swing arm 65, Thus, the lock body 40 was configured. As shown in FIG. 9, the guide base 43 is provided with a pair of upper and lower brackets 66. The swing shaft 67 is supported by both brackets 66, and the swing arm 65 is supported by the swing shaft 67. The entire lock body 40 is supported so as to be swingable around the swing shaft 67. The spring 42 is disposed between the guide base 43 and the end of the swing arm 65 on the passive portion 48 side, and biases the lock body 40 in the unlocking direction. The passive portion 48 can swing along with the carriage 13, and when swinging in the counterclockwise direction toward FIG. 8, the lock portion 47 is moved from the unlocked position (state shown in FIG. 10) to the locked position (FIG. 8). To the state shown in FIG. The tip of the passive portion 48 is rounded into a semicircle.

  In a state where the hook-shaped lock portion 47 is located at the unlocking position, the front end of the swing arm 65 is received by a stopper piece 68 provided on the guide base 43. After the carriage 13 comes into contact with the passive portion 48 from this state, the passive portion 48 is pushed by the peripheral wall of the carriage 13 so that the lock portion 47 relatively enters the entrance 54, and Face to front and back. When the carriage 13 further approaches the lock body 40, the lock body 40 swings in the counterclockwise direction against the urging force of the spring 42 and switches to the locked posture. Since the distal end 70 of the lock portion 47 switched to the locked posture is caught by the joint surface 57 of the locked portion 41, the carriage 13 can be locked so as not to move. Since others are the same as the previous embodiment, the same reference numerals are assigned to the same members, and descriptions thereof are omitted. The same applies to the following embodiments.

  FIG. 11 shows another embodiment of the lock part 47 and the locked part 41. In this case, the joint surface 58 of the lock portion 47 is formed as a convex surface having a V-shaped cross section, and the joint surface 57 of the locked portion 41 is formed as a groove surface having a V-shaped cross section. Thus, when each joint surface 57 and 58 of the lock part 47 and the to-be-locked part 41 is comprised with an uneven | corrugated body, in the state which made the lock body 40 into the lock attitude | position, both joint surfaces 57 and 58 will mutually fit, It is possible to more reliably prevent the carriage 13 that has received an external force from moving up and down. The cross-sectional shapes of the joint surfaces 57 and 58 of the lock portion 47 and the locked portion 41 can be changed to a partial arc shape, a trapezoidal shape, or a partial spherical shape, etc. It only has to be in a relationship.

  In the above embodiment, the carriage fixing mechanism is provided at each of the left and right stroke ends in the sub-scanning direction. However, it is not necessary, and the carriage fixing mechanism may be provided at at least one stroke end in the sub-scanning direction. The operation tool 62 does not need to be a push button, and may be a slide knob, a tilt switch knob, or the like.

DESCRIPTION OF SYMBOLS 11 Platen glass 12 Reading unit 13 Carriage 14 Moving mechanism 29 Frame 40 Locking body 41 Locked part 42 Spring 44 Operation part 47 Locking part 48 Passive part 54 Entrance 55/56 Cam surface 57/58 Joint surface

Claims (6)

A document table provided with a platen glass;
A reading unit that is arranged inside the document placing table and reads a document placed on the platen glass;
A carriage for accommodating the reading unit;
A moving mechanism for moving the carriage in the sub-scanning direction,
A carriage fixing mechanism that restrains at least one stroke end of the document placing table in the sub-scanning direction as a restraining position and restrains the carriage so as not to move is provided at the position.
The carriage fixing mechanism is
In conjunction with the movement of the carriage toward the restraint position, the carriage can be automatically locked,
An image reading apparatus, wherein the carriage can be automatically unlocked in conjunction with an operation of moving the carriage away from the restraining position. The carriage fixing mechanism is
A locked portion provided on the carriage;
A lock body supported by the frame of the document table and displaceable between a lock position that contacts the locked portion and a lock release position that is separated from the locked portion;
A spring for urging the lock body toward the unlock position;
The lock body is
A passive unit that inherits the movement of the carriage toward or away from the restraint position;
In conjunction with the displacement of the passive part, it comprises a lock part that contacts or separates from the locked part,
2. The image reading apparatus according to claim 1, wherein the lock portion is in contact with the locked portion and the carriage is locked so as not to move in a state where the carriage is located at the restraining position. The lock body is supported by the frame of the document table so as to be slidable back and forth between a lock position and an unlock position.
On the peripheral wall of the carriage facing the locked part,
An entrance allowing the lock to enter and exit;
An operation unit for operating the passive unit is provided,
Each of the passive unit and the operation unit is provided with a cam surface that converts the movement of the carriage into a sliding operation in the locking direction of the lock body,
In the process in which the carriage approaches the restraint position, the lock portion enters the entrance and faces the locked portion,
3. The image reading apparatus according to claim 2, wherein in a state where the carriage is located at the restraining position, joint surfaces of the lock portion and the locked portion are in contact with each other to lock the carriage so as not to move. The lock body is
A swing arm supported so as to be swingable by a frame of the document table; the passive portion provided at one end of the swing arm;
A hook-shaped lock portion provided at the other end of the swing arm,
In the peripheral wall of the carriage facing the locked portion, an entrance is provided that allows the locking portion to enter and exit,
In the process in which the carriage approaches the restraint position, the passive part is pushed by the peripheral wall of the carriage,
The lock part that has entered the inside of the entrance and the locked part are opposed to each other,
3. The image reading apparatus according to claim 2, wherein the lock portion is hooked on the locked portion and the carriage is locked so as not to move in a state where the carriage is located at the restraining position. An operation tool for activating the moving mechanism is disposed on the operation panel,
5. The image according to claim 2, wherein the carriage is moved to a restrained position by the moving mechanism and is immovably locked by the carriage fixing mechanism in a state where the operation tool is switched to an on state. Reader. Contact glass is disposed adjacent to the platen glass,
An automatic document feeder for feeding a document toward the upper surface of the contact lens is provided on the platen cover,
The document reading position where the carriage is positioned below the contact glass and the restraining position are matched,
6. The image reading apparatus according to claim 2, wherein the carriage positioned at the document reading position is fixed by the carriage fixing mechanism.

Images