JPS6136732A - Automatic original size detector of copying machine - Google Patents

Abstract

PURPOSE:To perform original size detection and exposure simultaneously with one scanning operation by scanning an original positioned to a registration guide provided in the side opposite to the home position. CONSTITUTION:The left end of an original 2 is matched to a registration guide 5 to place the original 2 on a platen 3, and a light source 6 is not lit and a carriage 7 starts scanning, and an identifying lamp 11 is lit and is moved, and the reflected light from a recognizing member 10 is detected by a detector 12. When the carriage 7 is moved by a length l1, it is covered with the end part of the original 2, and the reflected light from the recognizing member 10 disappears, and a control circuit calculates the length l1 in accordance with the time of light incidence on the detector 12 and the moving speed of the carriage. Thus, an original size l2 is obtained by the length l1, original size detection and exposure are performed with one scanning operation, and the copying time is shortened and the work efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic document size detection device for a copying machine that detects the size of the document at the same time as the document is exposed.

2. Description of the Related Art Conventionally, in a copying machine that automatically detects the size of an original to be copied, there is a KI! There is a system that detects the size of a blank scanned document and exposes the document in the next main scan.

Problems to be Solved by the Invention However, the copying machine described above has a problem in that the copying speed is slow because an empty scan is performed every time a copy is made.

This invention was made for the purpose of improving the above-mentioned problems.

Means and Effects for Solving the Problem The document aligned with the registration guide provided on the opposite side of the home position is scanned from the home position side, and the document size is detected from the distance from the home position to the leading edge of the document. Particularly, an automatic document size detection device for a copying machine that can detect the document size and expose the document at the same time in one scan.

Embodiment One embodiment of the present invention will be described in detail with reference to the drawings. In the figure, 1 is a main body of a copying machine, on which a platen 3 on which a document 2 to be copied is placed and a platen cover 4 which can be opened and closed freely are provided. ing. A registration guide 5 for aligning the document 2 is provided on the left side of the platen 3, and a light source 6 is provided below the platen 3 on the opposite side of the registration guide 5, that is, on the right side. is provided. The light source 6 is installed on a carriage 7 that is movable to the left along the lower surface of the platen 3, and illuminates the document 2 on the platen 3, and the light reflected from the document 2 is optically The light is guided to the photoreceptor 9 by the system 8 .

On the other hand, on the carriage 7, there is an identification lamp 11 that illuminates a tape-shaped recognition member 1° attached to the lower surface of the platen cover 3, and a size detector consisting of a light receiving element that receives light reflected from the recognition member 1o. 12 is provided, and the size of the document 2 is detected as follows.

Place the left end of the document 2 to be copied (registration) on the platen 3 in line with the L/-john guide 5, close the platen cover 4, and press the copy start switch (not shown), the light source 6 will turn on. The carriage 7 starts scanning without being scanned. At this time, the recognition lamp 11 is turned on and moves together with the light source 6, and the size detector 12 receives the reflected light from the recognition member 10. The size signal detected by the size detector 12 is taken into a control circuit (not shown), and the time during which the size signal is input is counted. Thereafter, when the carriage 7 has moved a distance t1, the recognition member 1 touches the edge of the document 2.
0 is covered, the recognition member 10 is sent to the size detector 12.
The control circuit determines the moving distance 1. from the time of entry into the size detector 12 and the moving speed of the carriage 7. Calculate. tiTotal moving distance t of carriage 7
Since we know in advance, 1-1. From the size t of manuscript 2
, is calculated. Note 1-1. +1. becomes.

The original size signal obtained by the above calculation is output to each control system, and the lighting time of the light source 6 and the paper size are determined. Thereafter, while the carriage 7 moves a distance t, the light source is turned on and the original 2 is exposed to light, and a sheet matching the size of the original 2 is fed from a paper feeder (not shown) to perform copying. become.

Effects of the Invention As detailed above, this invention is capable of detecting the size of an original placed on a platen and exposing it in a single scanning operation, and is therefore superior to the conventional method of exposing an original after a blank scan. In comparison, copying time can be significantly reduced. This allows for efficient copying work.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, with FIG. 1 being a sectional view of a copying machine, and FIG. 2 being an explanatory diagram of its operation. 2 is a document, 5 is a registration guide, and 6 is a light source.

Claims (1)

[Claims] A registration guide 5 is provided on the side opposite to the home position of the light source 6 that exposes the original 2 to be copied, and the original 2 aligned with the registration guide 5 is scanned from the home position side, and the original 2 is scanned from the home position. An automatic document size detection device for a copying machine that detects the size of the document 2 from the distance l_1 to the leading edge.