JPH0143176Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a shredder for shredding documents, etc., and is particularly applicable to a shredder that shreds documents, etc. Regarding a detection device.

(b) Prior Art Figure 3 shows a schematic structural diagram of a conventionally commonly used shredder. On the upper surface of the shredder main body 1 is an input port 2 into which paper sheets to be processed are input.
is formed, and two sets of cutter rollers 3 are installed inside this inlet 2 so as to partially overlap each other. The cutter roller 3 is made up of a plurality of disc-shaped rotary blades connected in the axial direction. At the bottom of the main body 1, a storage box (accommodation section) 4 is installed to store paper sheets (cutting waste) cut into stripes by the cutter roller 3. This storage box 4 can be taken out by opening a door (not shown) provided on the side of the main body 1, and the stored cut waste can be disposed of. A micro switch 5 is installed on the inner wall of the main body above the housing box 4 with its hinge lever 6 facing downward. The tip of the hinge lever 6 is located at the upper part of the inside of the storage box 4.

In this shredder, the cut scraps cut by the cutter roller 3 are accumulated in the storage box 4, and when the height of the pile reaches the position of the hinge lever 6, the hinge lever 6 is pushed up by the paper sheets and rises, and the micro switch 5 is activated. turns on. A control section (not shown) detects this on state and performs actions to cope with the full paper, such as stopping the operation and generating an alarm.

(c) Problems to be solved by the invention In such a shredder, the hinge lever 6
protrudes from the top of the storage box 4, so the storage box 4
Hinge lever 6 that is easy to contact when inserting and removing
There was a risk of damaging it. For this reason, there was a problem that care was required when loading and unloading, resulting in poor workability.

In addition, the hinge lever 6 prevents the cut scraps from falling evenly, and the area directly below the hinge lever 6 is deposited in a concave state, resulting in a delay in full paper detection and the risk of overflowing the cut scraps into the main body of the apparatus. .

In addition, the hinge lever 6 due to mechanical vibrations
There were also problems with the switch's lifespan being shortened, as the switch could oscillate and malfunction.

In view of these problems, the object of this invention is to provide a paper shredder full paper detection device that can accurately detect full paper using an optical method.

(d) Means for solving the problem This invention provides a shredder having a cutting section for cutting input paper sheets, and a storage section for accumulating and storing the shredded paper sheets. A light-emitting element that emits light of a specific wavelength and a light-receiving element that receives light of the specific wavelength are provided at the upper end portion, respectively, facing the housing part, and a drive circuit that drives the light-emitting element at a specific frequency; It is characterized by comprising: a filtering means for filtering a component of the specific frequency out of the light received by the element; and an outputting means for outputting a message indicating that the storage section is full when the filtering output exceeds a certain value. do.

(e) Effect In the shredder full sheet detection device of this invention, the light emitting element and the light receiving element are installed facing the housing part (so that light does not directly enter the light receiving element from the light emitting element), and the light emitting element is set at a specific frequency. irradiates the interior of the housing with light of a specific wavelength modulated by

This light is reflected on the upper surface of the cut scraps accumulated and accommodated in the storage section, and the light receiving element receives the reflected light. The amount of light received becomes stronger as the height of the pile of cutting debris increases (the closer the reflecting surface is).

The filtering means filters only the component of the specific frequency from the light received by the light receiving element (this removes the influence of external light and extracts only the light reflected from the light emitting element → cutting waste).

It is determined whether the output of this specific frequency component is above a certain value (the intensity of the reflected light when the top of the cutting waste is at the top of the storage section), and when it is above the certain value, it is determined that the paper is full. Output (output means).

(f) Embodiment FIG. 1 is a schematic structural diagram of a shredder to which a full sheet detection device according to an embodiment of this invention is applied. In the structure, the same parts as the conventional shredder shown in FIG. 3 are given the same numbers, and the explanation will be omitted. A shielding plate 7 is provided between the cutter roller 3 and the storage box 4 to block light from the outside.
The shielding plate 7 is provided with an opening 7a for dropping cut paper sheets into the storage box 4. A light emitting element 8 and a light receiving element 9 are provided below the shielding plate 7. Both the light emitting element 8 and the light receiving element 9 are installed toward the inside of the housing box 4 (downward). As a result, the light emitted by the light emitting element 8 does not directly enter the light emitting element 9, but the light reflected from the upper end of the cut scraps accumulated and stored in the storage box 4 enters.

FIG. 2 is a diagram showing the circuit configuration of the full paper detection device. The light emitting element 8 is composed of a light emitting diode 11 that emits light including infrared rays and a visible light cut filter 12 that cuts out light with a wavelength shorter than infrared rays. An oscillator 10 that supplies an oscillating current of a specific frequency is connected to the light emitting diode 11. This oscillator 10 supplies an oscillating current of 3.3 kHz to the light emitting diode 11. That is, the light emitting element 8 irradiates the inside of the storage box 4 with infrared rays that are amplitude modulated at 3.3 kHz.

On the other hand, the light receiving element 9 consists of a photodiode and a visible light cut filter 13. Photodiode 14 is an element sensitive to infrared and visible light. The red filter 13 is for cutting sensitivity to light rays with wavelengths shorter than red. The photodiode 14
A resistor 15 is connected in series with +
A reverse voltage of V is applied. At this time, the voltage generated across the resistor 15 is supplied to the filter 16, and the voltage (output) filtered by the filter 16 is sent to the amplifier 17.
is input. This filter 16 is connected to the oscillator 1
This is a bandpass filter that filters only the component with an oscillation frequency of 0 (3.3kHz). The 3.3kHz component amplified by the amplifier 17 is rectified by the rectifier 18 and converted into a voltage value corresponding to its amplitude. This voltage is input to the compared terminal of the comparator 19. A voltage +V and a reference voltage setting resistor 2 are connected to the comparison terminal of the comparator 19.
A reference voltage set as 0 and 21 is input.
The comparator 19 outputs "H" when the voltage input from the rectifier 18 exceeds the reference voltage, and prompts the following operating section (not shown) to operate. It is possible to connect a drive stop circuit for the cutter roller 3, an alarm sounding circuit, etc. as the subsequent operating section.

Here, the voltage across the resistor 15 is determined by a photocurrent that is proportional to the amount of light received by the photodiode 14 (although it is not a proportional relationship in a mathematical sense, it is a monotonically increasing function). That is,
When the photocurrent increases, the voltage across both ends increases, and when the photocurrent decreases, the voltage across both ends decreases. Of this voltage change, only the 3.3 kHz component is filtered by the filter 16 and supplied to the amplifier 17. Thereby, only the component of the light emitted by the light emitting diode 11 out of the light received by the photodiode 14 can be extracted. Further, the amplitude of the filtered 3.3 kHz component (that is, the voltage value rectified by the rectifier 18) is proportional to the amount of light received by the photodiode 14. The reference voltage is set to a voltage value output by the rectifier 18 when the storage box 4 is full. Thereby, when the storage box 4 is full of cutting waste, the cutter roller drive stop circuit, alarm sounding circuit, etc. can be operated.

The filter 16 corresponds to the filtering means of this invention, and the comparator 19 corresponds to the output means of this invention. In addition, the +V and reference voltage setting resistor 2
The reference voltage set at 0 and 21 corresponds to the constant value of the present invention.

In this embodiment, the light-emitting element 8 and the light-receiving element 9 are placed facing each other on opposite sides within the main body 1, but the light-emitting element and the light-receiving element may be integrated and placed on one side. This completely eliminates the risk of light from the light emitting element directly entering the light receiving element.

Furthermore, in this example, by using infrared rays as the detection light, it was possible to reduce changes in reflectance due to the color of the cutting waste, further improving detection accuracy.

(g) Effect of the invention According to this invention, the amount of reflected light irradiated into the storage part is detected by a light emitting element and a light receiving element provided above the storage part, and based on this value, ), the detection piece (hinge lever)
It is possible to eliminate protrusions such as, etc., which prevents the accumulation of shredded paper sheets, and also facilitates loading and unloading of the storage section (disposal of shredded waste). Furthermore, by eliminating mechanically movable parts, the life of the detection device can be extended.

Furthermore, this device modulates the emitted light at a specific frequency and filters only this frequency component from the received light, thereby eliminating errors caused by external light (which does not have specific frequency components). can do.

[Brief explanation of the drawing]

Fig. 1 is a schematic structural diagram of a shredder to which a full-sheet detecting device according to an embodiment of the present invention is applied, Fig. 2 is a diagram showing the circuit configuration of the full-sheet detecting device, and Fig. 3 is a schematic diagram of a conventional shredder. It is a structural diagram. 8... Light emitting element, 9... Light receiving element, 10... Oscillator, 11... Light emitting diode, 12, 13...
Visible light cut filter, 14... photodiode, 16... filter, 19... comparator.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a shredder having a cutting section for cutting input paper sheets and a storage section for storing the shredded paper sheets in a pile, an upper end of the storage section: , a light-emitting element that emits light of a specific wavelength and a light-receiving element that receives light of the specific wavelength are each provided facing the housing part, a drive circuit that drives the light-emitting element at a specific frequency, and a drive circuit that drives the light-emitting element at a specific frequency; A filling of a shredder characterized in that it is provided with a filtering means for filtering the component of the specific frequency of the light, and an outputting means for outputting a message indicating that the storage section is full when the filtered output exceeds a certain value. Paper detection device. (2) The full sheet detection device for a shredder according to claim 1, wherein the light of the specific wavelength is infrared rays.