JPH04128737A - Method for measuring transmittance of original of diazo copying machine - Google Patents

Abstract

PURPOSE:To more exactly measure the transmittance of an original by measuring the transmittance of the inserted original by the light source light quantity detected when a 1st original detecting means detects the original and the transmitted light quantity detected when a 2nd original detecting means detects the original. CONSTITUTION:A light quantity detecting section 10 is held always in an operating state to store the light quantity detected when the 1st original detecting means 20 detects the original P as the light source light quantity I0, to store the light quantity detected when the 2nd original detecting means 30 detects the original P as the transmitted light quantity I and to measure the transmittance of the inserted original P by the stored light source light quantity I0 and the transmitted light quantity I. Then, the time after the light source light quantity I0 is stored before the transmitted light quantity I is stored is the short time by the operation that an operator inserts the original into the device and the light quantity just before the original is inserted is stored as the light source light quantity I0. The transmittance of the original is more exactly measured in this way.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for measuring document transmittance in a diazo copying machine.

[Conventional technology]

Conventionally, the original transmittance CI/I is determined by the light source light amount I0 and the transmitted light amount I. ) and controls the printing speed based on the original transmittance.

FIG. 2 schematically shows an apparatus for detecting the amount of light transmitted through an original used in a conventional method for measuring the transmittance of an original in a diazo copying machine.

This original transmitted light amount detection device is arranged on a paper feed table 90 of a copying machine, and includes a light source 11 and a light amount sensor 1 that are arranged to face each other with a gap G for inserting the original.
2, and a document detection means 50 provided behind the light amount detection section IO in the document insertion direction (on the left side of the drawing).
It has

The light source 11 is provided so as to be embedded in the paper feed table 90 of the copying machine, and the light amount sensor 12 and the document detection means 50 are provided in the opposing member 40.

The light amount detection unit IO is always kept in an operating state, detects the amount of light at regular time intervals, and updates the detected light amount value.

Measurement of document transmittance is performed as follows.

(2) The light amount detected by the light amount detection section IO when no document is inserted into the gap G between the light source 11 and the light amount sensor 12 is stored as the light source light amount I0.

(2) Insert the ground part (non-image part) of the original into the gap G along the original insertion direction (indicated by the arrow).

The amount of light detected by the light amount detection unit IO when the leading edge of the inserted document is detected by the document detection means 50 is stored as the amount of transmitted light (2).

(2) The original transmittance (1/I.) is measured using the stored light source light amount I0 and transmitted light amount I.

[Problem to be solved by the invention]

However, in the original transmittance measurement method as described above,
Light source light intensity■. The amount of time that elapses from memorizing the amount of transmitted light I to memorizing it is undefined, and it may take a certain amount of time to memorize it. There is a problem in that if it fluctuates, it is not possible to accurately measure the original transmittance.

The present invention has been made based on the above-mentioned circumstances, and an object thereof is to provide a method for measuring document transmittance of a diazo copying machine that can accurately measure document transmittance.

[Means to solve the problem]

In order to achieve the above object, the original transmittance measurement method for a diazo copying machine according to the present invention includes: a light amount detection section consisting of a light source and a light amount sensor provided so as to face each other across a document insertion gap; A document transmitted light amount detecting device including a first document detecting means provided at the front in the insertion direction and a second document detecting means provided at the rear in the document insertion direction from the light amount detecting section is used. is always kept in an operating state, and the amount of light detected when the first document detection means detects the document is the light source light amount (2).

The amount of light detected when the second document detecting means detects the document is stored as the amount of transmitted light ■, and the amount of the inserted document is determined by the stored light source light amount I0 and the amount of transmitted light I. It is characterized by measuring transmittance.

[Effect]

Light source light intensity■. The time from when is memorized to when the amount of transmitted light ■ is stored is an extremely short time due to the operation of the operator inserting the document into the device, and the amount of light immediately before the document is inserted is stored as the light source light amount I0. Therefore, the measured document transmittance is accurate.

〔Example〕

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

FIG. 1 is an explanatory diagram schematically showing an apparatus for detecting the amount of transmitted light of an original used in the method of measuring the transmittance of an original for a diazo copying machine according to the present invention.

This document transmitted light amount detection device is arranged on a paper feed table 90 of a copying machine, and includes a light amount detection section 10 consisting of a light source 11 and a light amount sensor 12, which are arranged to face each other with a document insertion gap G interposed therebetween, and a light amount detection section 10. The first document detection means 20 is provided in front of the IO in the document insertion direction (on the right side of the drawing), and the second document detection means 30 is provided in the rear of the light amount detection section 10 in the document insertion direction (left side in the drawing). are doing.

The light source 11 is provided so as to be embedded in a paper feed tray 90 of the copying machine, and the light amount sensor 12, the first document detection means 20, and the second document detection means 30 are provided in the opposing member 40.

The light amount detection unit 10 is always kept in an operating state, and
The light amount is detected at m5ec intervals and the detected light amount value is updated.

In this embodiment, the measurement of document transmittance is performed as follows.

■Insert the base portion (non-image portion) of the document P into the gear G along the document insertion direction.

When the leading edge of the document P is detected by the first document detection means 20 (FIG. 1(A)), the light amount detected by the light amount detection unit IO is equal to the light source light amount 1. It will be memorized.

(2) Insert the original P further backward in the original insertion direction.

When the leading edge of the document P is detected by the second document detection means 30 (FIG. 1(b)), the document P is detected by the light amount detection unit l
It completely covers the optical path of O. ), the light amount detected by the light amount detection unit IO is stored as the transmitted light amount I.

(2) The original transmittance (I/I.) is measured based on the stored light source light amount I0 and transmitted light amount I.

The printing speed is then controlled based on the measured document transmittance.

The printing speed is controlled by controlling the rotational speed of the motor, which is the drive source for conveying the photosensitive paper. One way to do this is to monitor the rotation of the motor with an encoder and adjust the speed based on this. It uses PWM (Pulse Width Modulation).

According to the document transmittance measurement method of the diazo copying machine of this embodiment, the time from storing the light source light amount I0 to storing the transmitted light amount I is determined by the operation of the operator or by inserting the document P into the device. This is an extremely short period of time determined by the speed, and the measured document transmittance is accurate because it is stored as the light intensity just before the document P is inserted or the light source light intensity I0.

〔Effect of the invention〕

According to the original transmittance measurement method for a diazo copying machine of the present invention,
Since the light intensity just before the original is inserted is stored as the light source light intensity I0, accurate original transmittance can be measured, and by controlling based on the measured original transmittance, an appropriate printing speed can be obtained. .

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an outline of a document transmitted light amount detection device used in the document transmittance measuring method for a diazo copying machine according to the present invention, and FIG.
The figure is an explanatory diagram showing an outline of a document transmitted light amount detection device used in a conventional document transmittance measurement method for a diazo copying machine. lO...Light amount detection section 11...Light source 12...
-Light sensor 20...first document detection means 3
0... Second document detection means 40... Opposing member 50
...Original detection means

Claims (1)

[Scope of Claims] A light amount detection section including a light source and a light amount sensor, which are provided to face each other with a document insertion gap interposed therebetween; a first document detection means provided ahead of the light amount detection section in the document insertion direction; A document transmitted light amount detection device includes a second document detection means provided behind the light amount detection section in the document insertion direction, the light amount detection section is always kept in an operating state, and the first document detection means The amount of light detected when the second document detecting means detects the document is stored as the light source light amount I_0, and the amount of light detected when the second document detecting means detects the document is stored as the amount of transmitted light.
A document transmittance measuring method for a diazo copying machine, characterized in that the document transmittance of an inserted document is measured using the stored light source light amount I_0 and the transmitted light amount I stored as I.