JPS5961363A - Original reading device - Google Patents

Abstract

PURPOSE:To shift accurately, a carriage, by driving directly the 1st and the 2nd carriages by availing individual flexible pulling member by individual motors. CONSTITUTION:In shifting the 2nd carriage stepwise in the X direction to read the original, a motor 19 is driven while power is applied to a motor 23 and it is stopped, and a pulley 13 is intermittently turned counter clockwise. In forwarding the 2nd carriage in the X direction, the motor 19 is driven to turn clockwise the pulley 13. In forwarding the 1st carriage 8 in the Y direction, the motor 23 is driven to turn a pulley 27 counter clockwise and in returning the 1st carriage 8, the pulley is turned clockwise. At the sub-scanning forward, the power is applied to the motor 19, the shift of the 2nd carriage is regulated and the home position reading of the original is kept stably.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for reading fixed originals in so-called digital copying machines, facsimile IJs, and the like.

There are various types of reading optical systems for fixed document placement.
In the reading system according to the present invention, a reading system that forms an image of a document to be read on a solid-state imaging system such as a CCD using a lens, converts the image into electricity, is mounted integrally on a carrier, and is mounted below the document table. In a device that performs two-dimensional movement reading, a movable reading device is made up of a small image sensor and a short focal length lens, and this movable carriage is moved back and forth in the main scanning direction and also moved in the sub-scanning direction. The object of the present invention is to improve the drive system in such a reading system to enable accurate two-dimensional scanning and high-speed reading scanning.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram illustrating the main parts of an embodiment of the present invention, as viewed in the main scanning direction (X direction), that is, a direction perpendicular to the sub-scanning direction (Y direction), and FIG. 2 is an illustration of the same embodiment. FIG. 6 is a perspective view of the main part of the same embodiment as viewed in the sub-scanning direction, that is, a direction perpendicular to the main scanning direction.

In the figure, O is a document to be read that is placed stationary on a document table glass 1 fixed to a box 2 of the main body of the document reading apparatus. 3 is a second movable carriage.

A small lamp 4, a mirror 5, a short focal length lens 6, and a CCD 7 are fixed to the carriage 6.

The light from the document 0 illuminated by the lamp 4 is reflected by the mirror 5 in a direction parallel to the document placement surface of the document table and is directed toward the lens 6. The lens 6 forms an optical image of the document on the light receiving surface of the CCI) '7, on which a large number of dotted light receiving elements are arranged in a line.

The CCD 7 self-scans this image in the direction in which the light-receiving elements are arranged, and forms an electric signal corresponding to the image. Use this signal (
・The desired image is printed out.

The above second movable carriage 2 is attached to the first movable carriage 8.
It is mounted so as to be relatively movable in the direction (the left-right direction in FIG. 2, which is a direction parallel to the document placement surface of the document table 1). That is, 9 is a sliding bearing fixed to the second movable carriage 6, and this bearing 9 is slidably fitted to a linear guide rail 10 fixed to the first movable carriage 8. The rail 10 is oriented in the X direction. Therefore, 11th = J moving carriage 6
is movable relative to the second movable carriage 8 in the X direction under the guide of the rail 100.

The second movable carriage 6 also moves i'' in the Y direction (the left-right direction in FIG. It is. Specifically, a sliding bearing 11 is fixed to the 1'5J moving carriage 8, and this bearing 11 is slidably fitted into a linear guide rail 12 fixed to the box body 2 of the main body of the device. I'm being forced to do it. The rail 12 is oriented in the Y direction. Therefore, if the first movable carriage 8 is moved in the Y direction under the guide of the rail 12, the second movable carriage 6 will be moved in the Y direction.

Now, the arrangement direction of the large number of light receiving elements of the CCI) 7 is made to correspond to the Y direction. In other words.

When each light-receiving element of the CCD 7 is projected onto the document placement surface of the document table 1 by the lens 6 and mirror 5, the projected images of each light-receiving element are aligned in a line in the Y direction. △l in Fig. 1 is the array length of the above-mentioned large number of light-receiving element projection images, in other words, at one time, the image of a portion of the width of a length of △l of the original 84o is displayed on the CCD.
The image is formed on the light receiving element row 7 and converted into an electrical signal. The second movable carriage 6 is first moved stepwise in the X direction under the guidance of the rail 1o while the first movable carriage 8 is stopped. The robot moves by repeatedly moving a predetermined minute distance in the X direction and stopping for a predetermined short time. Therefore, when the above stop occurs, the CCI
) performs self-scanning and reads a very narrow portion of the document having a length of Δl. When this reading is completed, the carriage 6
moves in the X direction by the predetermined minute distance, and this minute distance is set in accordance with the resolution required for the image to be reproduced. As described above, when the carriage 6 is moved forward in the X direction and the reading from one end to the other end in the incoming direction in the area of width △l in the cool phase 0 becomes redundant, the carriage 5 moves forward in the X direction. Move backwards, then △l in the Y direction
, or first move a distance △l in the Y direction and then move back in the X direction, or move it a distance △l in the Y direction and move back in the X direction at the same time. , by moving the document back and forth in the X direction as described above, an area having a width of Δ4 that is in contact with the read document area TMi is read in the X direction from +':M to the other end. (In addition, the second carriage 3 (7) distance of △l in the
△1 row by 5 degrees) Repeat this operation to read the entire surface of the document from one end to the other in the Y direction and from one end to the other in the X direction, and then move the carriage. 6 moves backward in the X and Y directions and returns to the initial starting position.

When the carriage B moves in the Y direction, the VC is not scanned by the CCD&U, and the original is not read.

Incidentally, the image may be simultaneously reproduced by transmitting it to a very narrow width part of the document having a length of △4, or an area f having a width of Δg from one end to the other end in a certain direction. A portion of the information is stored in the memory circuit, and the carriage 6 moves back in the X direction to read the document 9rj area 1' adjacent to the above area.
JB (transfers the information to the memory circuit between the printer and the printer) Part of the information on the entire page is stored in the memory circuit, and after the entire document has been read, it is transmitted to the printer and the desired image is printed in one page. You may also set it to be out.

rM, in the above example, is faster than the forward movement speed of the carriage 6 in the X direction (i [Ii! + speed HB6 and the moving speed g in °C in the This reduces the time required to read the entire surface of the document.Alternatively, by moving the carriage roller forward in the X direction, an area of width △l from one end of the document in the X direction to the other After reading , next move the carriage 3 forward a distance of △l in the Y direction on the forward movement end point side, and then drive the carriage 6 in the X direction with the same step movement as in the forward movement, that is, the same as in the forward movement. It is also possible to repeat the movement of moving a very small distance and stopping for a short period of time as in the forward movement, and also during this backward movement, to scan the original by self-scanning the CCD during the short stop.In any case,
Since the movable reading head composed of 6 to 70 means only needs to read a small area of a document at a time, it is small and lightweight, and can be moved reliably in steps.

Next, a drive mechanism for moving the carriage 6 in the X direction and the Y direction will be described. The mechanism described below can move the carriage 6 in both the X direction and the Y direction using two flexible traction members, and the first carriage 8 and the second carriage 3 are connected to the first carriage 8 and the second carriage 3. A motor for moving the second carriages 8, 3 is not mounted, and therefore the weight of these movable bodies can be reduced and the accuracy and speed of movement can be improved.

In FIG. 6, 16-17 are timing pulleys. Pulley 16 was placed in position. The pulse morph, which can rotate in both forward and reverse directions, is fixed to the output shaft of (19).The pulley 14 is rotatably arranged in a fixed position.The pulleys 13 and 14 do not mechanically interfere with the first carriage 8. Therefore, it is preferable that the pulleys 15, 16, and 17 are arranged further outside the both ends of the movement range of the first carriage 8 in the Y direction. The pulleys 15 and 17 are mounted on the first carriage 8 at one side end in the X direction, and the pulley 16
is placed at the other end. Pulley 15,1
7. The pulley 16 is arranged so as not to mechanically interfere with the movement of the second carriage 6 on the first carriage 8. Therefore, the pulleys 15, 17, and 16 are
It is preferable that the movement range in the X direction be further outside. Reference numeral 18 denotes a substantially endless timing belt, which is wound in the order of pulleys 1, 15, 16, 17, and 14. Pulley 1, 150, pulley 17,
14, between the pulleys 14 and 13, the belt 1B is stretched parallel to the rail 12, in other words, in the Y direction; is stretched parallel to the rail 10, in other words, in the X direction. Belt 18 is Boo'J 15,1
6, it is fixed to a hanging plate 22 fixed to the second gear rigidity B (see figure #!1). Boo IJ 16,
The belt 18 may be fixed to the hanging plate 19 between the belts 17 and 17.

Another pulse motor A2 is set at the fixed position shown in the figure, and there is also a timing pulley 26 that can rotate on a shaft (not shown) attached to the main body frame, and is fixed to the output shaft of the motor 23. The timing belt 28 is passed parallel to the rail 12 between the timing pulley 27, and the belt 28 and the first carriage 8 are connected below the screw 29Q).
are combined. The first carriage 8 is movable on the rail 12 in the Y direction by forward and reverse driving of the pulse motor 26Δ. In the above embodiment, a substantially endless belt 1B (both ends of one end belt may be connected at the connecting portion) is stretched to form a T-shaped closed loop, and The carriage is moved two-dimensionally without mounting a motor on either the first carriage 8 or the second carriage 6.

In the above, the second carriage 6 is
When moving forward in steps in the direction, the motor 26 is passed through '11. In the held and stopped state, the motor 19 is driven to intermittently rotate the pulley 16 counterclockwise. When the second carriage 6 is moved back in the X direction, the motor 1
Drive 9 to rotate pulley 1 clockwise. On the other hand, to move the first carriage 8 forward in the Y direction, the motor 26 is driven to rotate the pulley 27 counterclockwise, and to move the first carriage 8 backward, the pulley 27 is rotated clockwise.

The motor 19 is kept energized during this sub-scanning forward movement, and the second
The movement of the carriage 6 is regulated to stably maintain the home position reading position of the document.

After the sub-scanning movement has been correctly performed by the required number of pulses, the motor 19 is made to apply pulses for the above-mentioned main-scanning forward movement while the motor 23 is energized and then stopped.

By this repeated operation, the entire area of the document is brought into a phase state of 110 degrees.
The reading is completed at high speed until the end, but since the reading system requires minute displacement feeding, there is no backlash such as that occurring between gears, or backlash that can be seen in gaps between gear grooves. Pulse motors can provide continuous high-precision feeds without any need for movement, and are lightweight because no motor is mounted on the movable body. It is possible to achieve high-speed driving by 9' function. Further, as mentioned above, the tM accuracy can be maintained correctly and easily by applying current braking using the pulse motion process.

In this example, the pulley 1 is rotated in the opening direction (while the second carriage 6 is moving backward in the X direction, the motor 26 is driven to rotate the pulley 27 in the counterclockwise direction,
The first carriage 8 may be moved forward in the Y direction by a distance Δe. The second carriage 6 moves in a direction that combines both the X and Y directions to reach the forward movement starting point position for new reading, and the second carriage 3 moves backward only in the YX direction and then only in the Y direction. A rectangular movement method of the second carriage B, in which the second carriage is first moved forward only in the Y direction and then moved back only in the X direction, has the effect of shortening the document reading time.

Incidentally, as the motors 19 and 23, an I) C motor whose rotation angle is controlled using an encoder as in the previous example may be used.

Furthermore, in the above example, a wire may be used instead of the timing belt, and an energized wire pulley may be used instead of the timing pulley.

In addition, the above-mentioned examples include ordinary monocular lenses, etc.
Harens, focusing optical transmitter (Selfoc: product name)
It is also possible to replace the imaging optical system with an imaging optical system in which a plurality of small-diameter imaging elements such as the above are bundled in a row or in a play shape.

Furthermore, in FIG. 6, the X direction may be the sub-scanning direction and the Y direction may be the main scanning direction. That is, the first carriage 8 may be reciprocated in the width direction of the document to perform main scanning, and the sub-scanning may be performed by moving the second carriage in the length direction of the document. The lifting weight and the arrangement direction of the many dot-like light receiving elements of the image sensor are arranged corresponding to the X direction in FIG. In other words, X in Figure 2 becomes Y, and Y in Figure 1
You can read this by replacing ``X'' with
You can read it by replacing 3 and 23 with 19.

In any case, according to the present invention, since the first and second carriages are directly driven by motors on their respective sides using separate flexible traction members, the movement of the carriages is accurate and fast. This enables high-speed reading and image reproduction. Also, an image sensor.

Since the imaging optical system is held integrally and moved two-dimensionally to read a small number of originals (7), it is only necessary to illuminate a small area of the original, so it is possible to correct uneven illumination on the original surface. It is unnecessary or simple, and has many useful effects.

[Brief explanation of drawings]

FIG. 1 is a diagram of an embodiment of the present invention viewed in the X direction, FIG. 2 is a diagram of the same embodiment viewed in the Y direction, and FIG. 6 is a perspective view of essential parts of the embodiment. 1 is a document table, 3 is a second carriage, 6 is a lens, 7 is a solid-state image sensor, 8 is a first carriage, 1B is a timing belt, 19 is a motor, 23 is a motor, and 28 is a timing belt. Applicant Canon Co., Ltd. Agent Gi Marushima -・i,',')-1(-)・

Claims (1)

[Claims] A fixed document table on which a document to be read is placed stationary; a first movable carriage movable in the sub-scanning direction or the main scanning direction with respect to the fixed document table; a second movable carriage mounted so as to be relatively movable in the sub-scanning direction or the sub-scanning direction; and an image sensor supported by the second movable carriage, in which a large number of dot-shaped light receiving elements are arranged in a direction corresponding to the sub-scanning direction. an imaging device that converts the original information into an electric number, which is arranged in 1. A 1st (7) iiJ that connects the 1st and 2nd 12 separate gear motors that are not mounted on the 2nd i'J moving carriage, the 1st drive motor, and the 2nd 1st fiJ moving gear ridge. Looking down at the flexible heavy traction member second drive motor and the 20th flexible traction member system that connects the 20th J moving carriage, the first and second drive motors are independently driven and controlled; and a document reading device in which the second carriage carrying an image sensor is repeatedly moved in the main scanning direction and subsequently in the sub-scanning direction.