JPH06217073A - Picture reader - Google Patents

Abstract

PURPOSE:To reduce the driving force of a platen roller by interposing a transparent endless sheet whose friction coefficient with a contact type image sensor is set small between the contact type image sensor and the platen roller. CONSTITUTION:A compact type image sensor 2 is always pressurized contact through a transparent endless sheet 7 whose friction with the compact type image sensor 2 is set small with a platen roller 1, and when the platen roller 1 is driven, the transparent endless sheet 7 and an original are simultaneously conveyed by friction with the platen roller 1, or the driving of a roller 6. In this case, the frictional force of the compact type image sensor 2 with the platen roller 1 is small, so that a load on the driving part of the platen roller 1 can be reduced. Also, the compact type image sensor 2 is always pressurized contact through the transparent endless sheet 7 with the platen roller 1, so that the fluctuation of the load due to the fluctuation of the frictional force can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus such as a facsimile machine and a copying machine.

[0002]

2. Description of the Related Art In a conventional image reading apparatus, as shown in FIG. 1, a document (9) passes through a pressure contact portion between a platen roller (1) and a contact image sensor (2) while the platen roller (1) is being driven. It is confirmed by the switch (5) that the contact type image sensor (2) is separated from the platen roller (1), and an unillustrated driving part of the platen roller (1) may receive an extra load. It was configured to disappear.

[0003]

However, according to this method, the presence / absence of a document at the pressure contact portion between the platen roller (1) and the contact image sensor (2) is turned on / off by the switch (5).
Platen roller (1) because it is judged by off
In the case where slippage or inclination of the document (9) occurs, the contact image sensor (2) is pressed against the platen roller (1) by pressing the platen roller (1) even though the document (9) is not in the pressure contact portion. There is a drawback in that the drive unit (not shown) of the roller (1) receives an extra load and the original document (9) cannot be fed normally.

[0004]

[MEANS FOR SOLVING THE PROBLEMS] A transparent endless sheet (7) having a small friction coefficient with the contact image sensor (2) is provided between the contact image sensor (2) and the platen roller (1). Scissors The driving force of the platen roller (1) is reduced.

[0005]

FIG. 2 shows an example of an image reading apparatus according to the present invention. The contact-type image sensor (2) is always in pressure contact with the platen roller (1) via the transparent endless sheet (7) which is set to have a small friction with the contact-type image sensor (2), and the transparent endless when the platen roller (1) is driven. The sheet (7) is conveyed simultaneously with the original by friction with the platen roller (1) or by driving the roller (6).

[0006]

According to the present invention, the contact type image sensor (2) and the platen roller (1) are pressure contacted with each other through the transparent endless sheet (7). Since the frictional force with the platen roller (1) is small, the load on the drive unit (not shown) of the platen roller (1) can be reduced, and the size and cost of the drive motor can be reduced. Further, since the contact image sensor (2) and the platen roller (1) are constantly in pressure contact with each other through the transparent endless sheet (7), there is no load change due to frictional force fluctuation, and there is slippage or inclination of the document (9). The problem that the load on the drive unit (not shown) of the platen roller (1) increases is eliminated. In addition, the original (9) is directly attached to the reading unit of the contact image sensor (2).
The original (9) is not rubbed on the transparent endless sheet (7).
Since the sheet is placed and conveyed, it is possible to prevent the read image from being soiled due to the soiling of the reading unit.

[Brief description of drawings]

FIG. 1 Conventional image reading apparatus for reducing frictional load

[FIG. 2] Image reading apparatus for reducing frictional load according to the present invention

[Explanation of symbols]

1 Platen Roller 2 Contact-type Image Sensor 3 Contact-type Image Sensor Pressure Contact Spring 4 Contact-type Image Sensor Separation Solenoid 5 Separation and Pressure Contact Timing Switch 6 Transparent Endless Sheet Conveying Roller (Drive or Drive) 7 Transparent Endless Sheet 8 Image Reading Device frame 9 manuscript

Claims (1)

[Claims] 1. An image reading apparatus comprising: a platen roller that conveys a document; a contact image sensor that is pressed against the platen roller; and a supply unit that supplies the document toward a pressure contact portion between the platen roller and the image sensor. An image reading device characterized in that a transparent endless sheet is sandwiched between a platen roller and an image sensor, and a document is conveyed on the transparent endless sheet together with the transparent endless sheet.