JPH04358648A - Device to detect amount of remaining recording sheet - Google Patents

Abstract

PURPOSE:To provide a recording paper remaining amount detecting device which detects a supply timing of recording papers before the recording papers are run short. CONSTITUTION:A device to detect an amount of remaining recording sheets comprises a light reflecting body 4 fixed to the moving spot of a recording paper placing plate 2 rocked or elevated along with the decrease of recording papers P, light irradiating means 11-14 to irradiate the light reflecting body 4 with light throughout the moving range of the light reflecting body 4, and a plurality of light receiving elements 21-24 to receive reflection light from the light reflection body 4 having a plurality of different detecting ranges, set throughout the moving range of the light reflecting body 4, and positioned in a corresponding detecting range. Based on detecting outputs from the light receiving elements 21-24, an amount of remaining recording papers P is detected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording paper remaining amount detection device for an image forming apparatus such as a printer or a copying machine.

0002

[Prior Art] Conventional copying machines generally detect when all the recording paper in a recording paper storage such as a paper cassette or paper feeding deck is used up, but how much recording paper is left in the recording paper storage? It is not detected whether there are any leftovers.

0003

[Problem to be solved by the invention] For this reason, the user
It is common for a user to suddenly run out of recording paper during a copying operation, stop the copying operation, and then find out that the recording paper has run out and replenish the recording paper.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording paper remaining amount detecting device that can determine when to replenish the recording paper before the recording paper runs out.

[0005]

[Means for Solving the Problems] A recording paper remaining amount detecting device according to the present invention includes a light reflector fixed at a moving position of a recording paper mounting plate that swings or goes up and down as the number of recording papers decreases, and a A light irradiation means that irradiates the light reflector with light over the moving range of the light reflector, and a light reflector that has a plurality of different detection ranges set over the moving range of the light reflector and is located in the corresponding detection range. It is characterized in that it includes a plurality of light-receiving elements for receiving reflected light, and detects the remaining amount of recording paper based on the detection output of each light-receiving element.

[0006] The light reflector is fixed to the moving position of the recording paper mounting plate with its light reflecting surface facing in the horizontal direction, and the light irradiation means and the plurality of light receiving elements are arranged around the recording paper mounting plate. It is preferable to arrange

[0007]

[Operation] Since a light reflector is fixed at a moving position of the recording paper mounting plate which swings or moves up and down as the number of recording papers decreases, the remaining amount of recording paper can be determined by knowing the position of the light reflector. The position of the light reflector is detected based on the detection outputs of a plurality of light receiving elements having a plurality of different detection ranges set over the movement range of the light reflector, and the remaining amount of recording paper is thereby detected.

[0008]

Embodiments Hereinafter, embodiments in which the present invention is applied to a copying machine will be described with reference to the drawings.

FIGS. 1 to 3 show a first embodiment of the invention. 1 to 3, the copying machine main body (not shown)
A recording paper mounting plate 2 is supported in a paper feeding cassette 1 mounted on the paper feed cassette 1 so as to be swingable about its rear end. The front part of the recording paper mounting plate 2 is connected to the front part of the recording paper mounting plate 2 and the paper feed cassette 1.
It is always biased upward by a spring 3 provided between it and the bottom wall. A plurality of recording papers P are placed on the recording paper mounting plate 2 in a superimposed state, and as the number of recording papers P decreases, the recording paper mounting plate 2 is moved by the force of the spring 3 so that the rear end of the recording paper P is lifted. It swings clockwise (direction shown by arrow A in FIG. 1) about the center.

At the center of the width of the front end of the lower surface of the recording paper mounting plate 2, there is a
A light reflector 4 such as a mirror is attached with its reflective surface facing forward. When the recording paper mounting plate 2 swings clockwise around the rear end as the number of recording papers P decreases, the light reflector 4 moves upward accordingly.

At the center of the front wall of the paper feed cassette 1, light is irradiated onto the light reflector 4 from the front of the paper feed cassette 1 over the entire moving range of the light reflector 4, and light reflected from the light reflector 4 is also reflected. Window 5 for transmitting the information to the front of the paper feed cassette 1
is formed.

On the main body side of the copying machine, in front of the window 5, there are a plurality of sets of light projecting elements for respectively detecting the light reflector 4 in a plurality of different detection ranges set over the moving range of the light reflector 4. Pairs of 11 to 14 (light irradiation means) and light receiving elements 21 to 24 are provided. Light projecting elements 11 to 14
For example, a light emitting diode is used. For example, photodiodes are used as the light receiving elements 21 to 24. A light projecting lens (not shown) is provided on the light projecting surface side of each of the light projecting elements 11 to 14, and a light receiving lens (not shown) is provided on the light receiving surface side of each of the light receiving elements 21 to 24.

The light emitting elements 11 to 14 and the light receiving elements 21 to 24 are arranged side by side at equal intervals in the vertical direction. The light emitting element array and the light receiving element array are
They are arranged at intervals in the left and right direction. The light emitting element 11 and the light receiving element 21, the light emitting element 12 and the light receiving element 22, the light emitting element 13 and the light receiving element 23, the light emitting element 14 and the light receiving element 24,
They each form a pair, and the light projecting element and light receiving element of each pair are arranged at the same height position.

Each of the light receiving elements 21 to 24 has a plurality of different detection ranges set over the moving range of the light reflector. Each of the light receiving elements 21 to 24 has a corresponding light emitting element 11 when the light reflector 4 is located in the corresponding detection range.
14 and reflected by the light reflector 4 enters.

Each light emitting element 11 to 14 and each light receiving element 2
1 to 24 indicate that the copying machine is turned on and the paper feed cassette 1 is
is driven when the is installed in the copying machine. Recording paper P
When the light reflector 4 is almost full, the light reflector 4 is located at a lower position within its movement range, at the height of the lowermost light projecting element 14 and light receiving element 24. In this case, the light emitted from the lowermost light projecting element 14 is irradiated onto the light reflector 4,
The reflected light is received by the light receiving element 24 at the lowest stage.

When the recording paper P decreases from its full state and the light reflector 4 reaches the height position of the second light emitting element 13 from the bottom and the light receiving element 23, light from the third light emitting element 13 from the top The emitted light is irradiated onto the light reflector 4, and the reflected light is received by the third light receiving element 23 from the top.

Further, when the recording paper P decreases and the light reflector 4 reaches the height position of the second light projecting element 12 from the top and the light receiving element 22, the light is emitted from the second light projecting element 12 from the top. The reflected light is irradiated onto the light reflector 4, and the reflected light is received by the second-stage light receiving element 22 from the top.

Furthermore, when the amount of recording paper P decreases and the remaining amount of recording paper P becomes very small, when the light reflector 4 comes to the height position of the light emitting element 11 and the light receiving element 21 in the uppermost stage, The light emitted from the light projecting element 11 is irradiated onto the light reflector 4, and the reflected light is received by the uppermost light receiving element 21.

In other words, as the remaining amount of the recording paper P decreases, the light receiving element 24 at the bottom, the light receiving element 23 at the third stage from the top, the light receiving element 22 at the third stage from the top, and the light receiving element 21 at the top stage. Light is received in sequence.

The detection output of each light receiving element 21 to 24 is sent to a control section (not shown). The control unit controls each light receiving element 21 to 2.
Based on the detection output of 4, the recording paper P in the paper feed cassette 1
The remaining amount is displayed on a display (not shown) provided on the main body of the copying machine. Therefore, from this display, the user can know the remaining amount of recording paper P in the paper feed cassette 1, and can know when to replenish the recording paper P before it runs out.

FIGS. 4 and 5 show a second embodiment of the invention. 4 and 5, the same parts as in FIG. 1 are given the same reference numerals, and their explanations will be omitted.

A light reflecting member 4 such as a mirror is fixed to the front end of the left side of the lower surface of the recording paper mounting plate 2 with its light reflecting surface facing left. From the front end of the left side wall inside the paper feed cassette 1, light is irradiated from the left side of the paper feed cassette 1 onto the light reflecting surface of the light reflector 4, and the reflected light from the light reflector 4 is reflected from the paper feed cassette 1. A window 6 is formed to transmit light to the left side.

On the main body side of the copying machine, there are provided a projector 31 (light irradiation means) and a projector for projecting light obliquely through the window 6 onto the light reflecting surface of the light reflector 4 over the movement range of the light reflector 4. A light lens 32 is arranged.

The main body side of the copying machine has a plurality of different detection ranges set over the movement range of the light reflector 4, and receives reflected light from the light reflector 4 located in the corresponding detection range. An image sensor 41 such as a CCD having a plurality of light receiving elements and a light receiving lens 42 are provided.

[0025] The projector 31 and the image sensor 41 are
It is driven when the copying machine is powered on and the paper feed cassette 1 is installed in the copying machine. As the number of recording sheets P in the paper feed cassette 1 decreases, the light reflector 4 rises. Among the plurality of light receiving elements of the image sensor 41, the detection voltage of the light receiving element that is receiving the reflected light from the light reflector 4 is higher than the detection voltage of the light receiving element that is not receiving the reflected light from the light reflector 4. Therefore, the position of the light reflector 4 can be detected based on the detection output of the image sensor 41.

The detection output of the image sensor 41 is transmitted to the control section (
(not shown). The control section determines the remaining amount of recording paper P in the paper feed cassette 1 based on the detection output of the image sensor 41, and displays the remaining amount of recording paper P on a display (not shown) provided in the main body of the copying machine. do. Therefore, from this display, the user can know the remaining amount of recording paper P in the paper feed cassette 1, and can know when to replenish the recording paper P before it runs out.

In the first and second embodiments, the light reflector 4 is fixed with its light reflecting surface facing forward or sideways,
Since the optical system for detecting the light reflector 4 is arranged around the paper feed cassette 1 rather than below the paper feed cassette 1, paper dust generated by the friction of the recording paper P during paper feeding is detected by the optical system. Hard to fall onto the system. Therefore, the remaining amount of recording paper can be accurately detected.

[0028]

According to the present invention, it is possible to know when to replenish recording paper before the recording paper runs out.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a horizontal sectional view showing a schematic configuration of a first embodiment of the invention.

FIG. 3 is a front view showing a light projecting element and a light receiving element as seen from the paper feed cassette side.

FIG. 4 is a vertical sectional view showing a schematic configuration of a second embodiment of the invention.

FIG. 5 is a horizontal sectional view showing a schematic configuration of a second embodiment of the invention. 1 Paper feed cassette 2 Recording paper mounting plate 4 Light reflector 11 Light emitter 12 Light emitter 13 Light emitter 14 Light emitter 21 Light receiver 22 Light receiver 23 Light receiver 24 Light receiver 31 Light emitter 41 image sensor

Claims (2)

[Claims] Claim 1: A light reflector fixed to a moving part of a recording paper mounting plate that swings or moves up and down as the number of recording papers decreases, and a light that irradiates the light reflector over the range of movement of the light reflector. It has an irradiation means, and a plurality of light receiving elements each having a plurality of different detection ranges set over the movement range of the light reflector and for receiving reflected light from the light reflector located in the corresponding detection range. A recording paper remaining amount detection device that detects the remaining amount of recording paper based on the detection output of a light receiving element. 2. The light reflector is fixed to a moving position of the recording paper mounting plate with its light reflecting surface facing in the horizontal direction, and the light irradiation means and the plurality of light receiving elements are connected to the recording paper mounting plate. A recording paper remaining amount detection device characterized in that the recording paper remaining amount detection device is arranged around the.