JPS63198473A - Image input device - Google Patents

Abstract

PURPOSE:To obtain the titled device of high reliability by attenuating a damped oscillation noise caused by the mechanical action of an optical system during a sliding by means of an electromagnetic brake device constituted of a magnet and a conductor. CONSTITUTION:Since a sensor fixing case 5 is driven in a sliding action by a stepping motor 13, its moving is discontinuous or its sliding comes intermittent, hence a mechanical sliding part is made to cause a mechanical damped oscillation noise by the internal energy of the optical part of the titled device constituted of a fluorescent lamp 2, a close-contact type rod lens array 3, a close-contact type linear image sensor 4, and the sensor fixing case 5. In order to suppress this mechanical oscillation, the electromagnetic brake device constituted of a guide rail 8 made of a conductor body such as aluminum or others and the permanent magnet 10, is provided, by which the mechanical oscillation of the titled device can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image input device that reads surface image information such as characters, graphics, photographs, etc. from the surface of a document.

[Summary of the invention]

The present invention suppresses mechanically damped vibration noise generated during mechanical sliding of the optical system in an image input device by providing an electromagnetic braking device in and around the mechanical sliding part of the optical system. This is how it was done.

[Conventional technology]

Conventionally, the mechanically damped vibration noise of the mechanical sliding parts of the optical system during operation of an image input device has been suppressed by applying an appropriate spring pressure to the mechanical sliding parts of the optical system. It is being

[Problem that the invention seeks to solve]

In the conventional technology described above, a spring pressure, which is a constant mechanical load, is always applied to the mechanical sliding parts of the optical system. This increases the load on the moving drive system, such as the stenbing motor, which increases current consumption and degrades the durability of mechanical sliding parts.In order to suppress mechanically damped vibration noise in the optical system, However, there was a problem that caused new disadvantages.

[Means for solving problems]

In order to solve the above problems, the present invention has developed an electromagnetic braking device consisting of a magnet and a conductor, without applying pressure using a spring, which would increase the load on the stepping motor of the drive system. This suppresses mechanically damped vibration noise, or so-called "flapping," in the optical system.

[Effect]

According to the above configuration, the mechanically damped vibration noise of the optical system of the image input device can be suppressed by the electromagnetic braking effect of the electromagnetic braking device.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a plan view of an embodiment of an image input device according to the present invention, FIG. 2 is a sectional view of FIG. 1, FIG. 3 is a partially enlarged view of FIGS. A fluorescent lamp 2 illuminates the original surface of the original to be placed on top, a close-contact type port 7 drain lens array 3 forms an image from the document surface into a same-size erect image, and the image from the close-contact rod lens array 3 is electrically converted. A contact type linear image sensor 4 that converts signals is attached to a sensor fixing case 5 and forms an optical system of an image input device. A round bar-shaped guide rail 7 whose both ends are fixed to the housing 6 is slidably penetrated through one end of the sensor fixing case 5.

Furthermore, as shown in FIGS. 2 and 3, the other end of the sensor fixing case 5 is provided with a guide rail 8 for smooth sliding on a flat guide rail 8 made of a conductive material fixed to the housing 6. A roller 9 and a U-shaped permanent magnet 10 for electromagnetic braking are attached.

Further, a part of the outer circumference of a timing belt 11 is fixed near the penetrating portion of the guide rail 7 of the sensor fixing case 5, and both ends of the timing belt 11 are connected to a timing pulley attached to a pulley 12 and a stepping motor 13. Supported by 14. On the other hand, the electronic circuit board 15 has a contact type linear image sensor 4.
A flexible cable 16 that outputs an image signal from the stepping motor 13 is connected to a signal line 17 of the stepping motor 13.

Next, to explain the actual operation, the original platen glass 1
When reading and inputting an image with a document placed on it, the stepping motor 13 receives a drive pulse signal from the electronic circuit board 15 and operates, and the timing pulley 1
4 and a sensor fixing case 5 to which a contact type linear image sensor 4 is fixed via a timing belt 11 and a pulley 12 are slid along guide rails 7 and 8 to read and input images. Time,
Since the sensor fixing case 5 is slid by the stepping motor 13, it inevitably moves discontinuously, that is, it slides intermittently. 4 and the sensor fixing case 5, the inertial energy of the optical system portion of the image input device acts to cause "flapping J", which is mechanically damped vibration noise, in the mechanical sliding part. In order to suppress this flapping J, an electromagnetic braking device is provided, which is composed of a guide rail 8 made of a conductive material such as aluminum, and a permanent magnet 10 attached to one end of the sensor fixing case 5. It is possible to suppress the above-mentioned "flapping" that inhibits ideal operation as an image input device.

The effect of magnetic braking 1 has almost no effect on the primary low-speed movement of the sensor fixing case 5 sliding by the stepping motor 13. In other words, the eddy current that becomes the electromagnetic braking force Almost never occurs on rail 8. On the other hand, when the stepping motor 13 performs a step operation and stops, a large eddy current is generated in the guide rail 8, which is a secondary high-speed movement that occurs when the stepping motor 13 stops, resulting in a large electromagnetic braking force. acts between the guide rail 8 and the permanent magnet 10, and acts to suppress the flapping of the sensor fixing case 5.

The electromagnetic braking described above is also called eddy current braking, and utilizes positional braking by the eddy current generated in a conductor placed in a magnetic field when the conductor moves relative to the magnetic field. , the braking action is proportional to the square of the strength of the magnetic field from the magnet, the cross-sectional area of the conductor, the speed of movement of the conductor, etc., and can be adjusted by arbitrarily setting the strength of the magnetic field from the magnet and the shape and material of the conductor. , it is possible to obtain the necessary braking force.

In addition, magnets are not only permanent magnets! The effect of electromagnetic braking can be similarly obtained using a magnet.

〔Effect of the invention〕

As explained above, the present invention eliminates the "flapping phenomenon", which is mechanically damped vibration noise that occurs when the optical system slides, from magnets and conductors in devices that perform manual image processing by sliding the optical system. The built-in electromagnetic braking device can suppress damping extremely efficiently, resulting in lower noise during image input, highly stable operation without mechanical shake, and no unnecessary load increase on the drive system. Therefore, there is a great effect that an image input device having high reliability can be realized without increasing current consumption.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of an image input device of the present invention;
2 is a sectional view of FIG. 1, and FIG. 3 is a partially enlarged view of FIG. 1. 1...Original table glass 2...Fluorescent lamp 3...Contact type Rondo lens array 4...Contact type linear image sensor-5...Sensor fixing case 6...Housing Body 7.8 Guide rail 9 Roller 10 Permanent magnet 11 Timing belt 12 Pulley 13 Stamping motor 14 Timing pulley 15 ...Electronic circuit board 16...Flexible cable 17...Signal line or more

Claims (1)

[Claims] In an image input device that inputs surface image information to an image sensor by mechanically sliding an optical system, mechanically damped vibration noise generated by the inertial energy of the optical system during mechanical sliding of the optical system is An image input device characterized in that the optical system is suppressed by an electromagnetic braking device constituted by a magnet and a conductor provided in the optical system and its surroundings.