JPH03135161A - Optical reader - Google Patents

Abstract

PURPOSE:To keep the length of the optical path relating the read of an original constant and to realize the suitable read of an original by fixing a 1st scanning member to a belt reaching a moving pulley from a motor and driving a 2nd scanning member. CONSTITUTION:Since a running system 9 is fixed to a belt 7 by a fixing member 8, the system 9 moves on a shaft 18 in response to the drive of the belt 7 at the same speed as that of the belt 7. Moreover, a running system 15 moves on the shaft 18 with a torque given from the belt 7 via moving pulleys 1, 2 and the moving quantity is set to be a half that of the running system 9. Then a light from a fluorescent light radiates an original 11 via a transparent scanning base 10 and its reflecting light is reflected sequentially in mirrors 14-16 of the running systems 9, 15 and made incident on a photodetector CCD 17. The length of the optical path relating to the read of the original 11 is kept constant, the constitution of the drive system is simplified and suitable reading is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical reading device that scans a document and reads a document image.

[Prior Art] An optical reading device that scans a document and reads the document image using a CCD or the like uses a first and second scanning device with a moving speed of 2:1 in order to keep the optical path length from the document to a light receiving section such as a CCD constant. It is known to have a second scanning member.

As such a device, for example, Utility Model Application No. 61-1241
There is one disclosed in Publication No. 53.

In this device, first and second scanning members with a speed ratio of 2:1 are provided on the shaft of a motor with a diameter ratio of 2:1.
It is belt driven by two pulleys.

Furthermore, instead of setting the pulley diameter ratio in this way, a device is also known in which a reduction gear is provided in a drive system including a motor.

In these conventional optical reading devices, a first mirror is provided on a first scanning member that is moved on a shaft by the driving force of a motor, and a first mirror is provided on a first scanning member that is moved on a shaft by a motor at a speed of 172 of the first scanning member. 2. Characters written on the document are read from the document to the COD via the second and third mirrors provided on the scanning member, and the optical path length related to this reading is kept constant. The focus related to this is ensured, and suitable document reading is realized.

[Problems to be Solved by the Invention] However, in such conventional optical reading devices, for example, two large and small pulleys are attached to the motor, two belts are used, or a reduction gear is used. It is complicated and has been an obstacle to making it thinner.

The present invention has been made to solve these problems, and an object of the present invention is to provide an optical reading device that has a simplified structure and can be made thin.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides two movable pulleys on the second scanning member, and a fixed pulley at a position where the motor is arranged with respect to the second scanning member. A belt with both ends fixed is placed on the opposite side of the
The present invention is characterized in that the motor and the other movable pulley are wound in this order and driven by the motor, and the first scanning member is fixed to a belt portion extending from the motor to the other movable pulley.

[Operation] In the optical reading device of the present invention, the driving force of the motor is transmitted to the first and second scanning members by a belt, and the first and second scanning members move on the shaft.

In this movement, since the belt and the first scanning member are fixed, the first scanning member moves at the same speed as the belt, while the second scanning member is moved at half this speed by the movable pulley. It will move at speed.

Therefore, the optical path length related to reading the original, that is, the optical path length from the original to the light receiving unit via the first to third mirrors is kept constant.

Therefore, in the present invention, pulleys having two types of diameter ratios, reduction gears, etc. are not required, and the device is configured to be simple and thin.

[Example code] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a schematic configuration of an optical reading device according to an embodiment of the present invention.

In this figure, two movable pulleys 1 and 2, a fixed pulley 3, a motor 4, and an idler 5 provided in the second traveling system (not shown) are shown, and furthermore, these The movable pulleys 1 and 2, the fixed pulley 3, the pulley 6 provided on the shaft of the motor 4, and the idler 5 include the motor 4.
A belt 7 is applied to supply driving force to a first traveling system (not shown) and a second scanning member.

FIG. 2 shows a more detailed configuration.

In this figure, a first running system 9 is shown that is fixed to the belt 7 by a fixing member 8. This first running system 9
A fluorescent lamp 12 irradiates light onto an original 11 placed on a transparent scanning table 10 disposed opposite to each other, and a second image (described later)
A first mirror 14 that reflects the light toward the mirror 13 is included.

Further, the second traveling system 15 including the movable pulleys 1 and 2 is
Furthermore, a second mirror 13 and a third mirror 16 are included.

The second mirror 13 and the third mirror 16 sequentially reflect the light beam supplied from the first mirror 14 and supply it to, for example, a CCD 17 fixed to a bottom chassis (not shown).

These first traveling system 9 and second traveling system 15 are both on the shaft 18! ! and is driven by a belt by a motor 4.

Further, the fixed pulley 3 is fixed on the side chassis 19, and both ends of the belt 7 are fixed on the side chassis 19 and 20, respectively.

The fixed pulley 3 is arranged on the opposite side to the motor 4 which is a driving source.

In this embodiment configured as described above, the fluorescent lamp 1
As shown by the dashed line in FIG.
4. CCD 1 via second mirror 15 and third mirror 16
7.

Next, the operation of this embodiment will be explained using FIGS. 2 and 3.

Note that in FIG. 3, the original 11 and the transparent scanning table 10 are omitted for the sake of simplicity.

First, when the motor 4 is driven, the pulley 6 provided on the shaft of the motor 4 rotates, and the belt 7 placed around the pulley 6 is driven.

Since the first running system 9 is fixed to the belt 7 by the fixing member 8, the shaft 1 is moved in response to the drive of the belt 7.
8 at the same speed as belt 7.

On the other hand, the second traveling system 15 connects the belt 7 to the movable pulley 1.
It moves on the shaft 18 by the power supplied through the drive system 2 and 2, but the amount of movement is 1/2 compared to the first travel system 9. That is, the moving speed of the second traveling system 15 is set to 1/2 of the moving speed of the first traveling system 9 by the movable pulleys 1 and 2.

Further, in this embodiment, the optical path that changes with the movement of the first traveling system 9 and the second traveling system 15 is the first mirror 1.
4 and the second mirror 13, and the distance between the third mirror 16 and C
This is the distance from CD17. For example, when the first drive system 9 moves by A from the initial position, the former moves by A/2.
and the latter decreases by A/2. That is, by driving the second traveling system 15 via the movable pulleys 1 and 2, the optical path length (the length of the dashed-dotted line in FIGS. 2 and 3) for reading the original 10 is kept constant. It will be.

Therefore, in this embodiment, from the original 10 to the CCD 1
The optical path length up to 7 is kept constant, ensuring focus and allowing suitable reading.

[Effects of the Invention] As explained above, according to the present invention, since the second scanning member is driven by a belt by a motor via two movable pulleys, the optical path length for reading a document can be kept constant. , the configuration of the drive system including the motor is simplified, and the device can be made thinner.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a schematic configuration of an optical reading device according to an embodiment of the present invention, FIG. 2 is a side view showing a detailed configuration of the device shown in FIG. 1, and FIG. FIG. 2 is a side view showing the arrangement during movement when scanning a document with the apparatus shown in FIG. 2; 1.2... Movable pulley 3... Fixed pulley 4... Motor 7... Belt 9... First traveling system 11... Document 13... Second mirror 4 5 6 7 8 1st mirror 2nd traveling system 3rd mirror OD shaft

Claims (1)

[Scope of Claims] A shaft disposed parallel to a scanning surface, a first scanning member having a first mirror and sliding on the shaft, second and third mirrors, and two movable pulleys, a second scanning member sliding on the shaft; and a second scanning member sliding on the shaft;
and a fixed light receiving unit that receives the reflected light reflected by the third mirror; a motor as a driving source; and a fixed pulley disposed on the opposite side of the second scanning member from where the motor is disposed. and both ends are fixed,
a belt that is wound around the one movable pulley, the fixed pulley, the motor, and the other movable pulley in this order and is driven by the motor; An optical reading device characterized by having a fixed scanning member.