JPH05112059A - Dust detector - Google Patents

Abstract

PURPOSE:To automatically inform a cleaning period when the function of the light sensor built in electronic machinery becomes impossible to ensure by the dust bonded to the photosensor. CONSTITUTION:The high and low levels of the sensor 1 built in electronic machinery are detected and the difference between the high and low levels is detected by a CPU 3 and, when said difference becomes a predetermined level or less, the maintenance period of the sensor 1 is informed to a user through an information means 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust detecting device which is provided in an electronic device such as a printer and is suitable for detecting dust adhering to a sensor.

[0002]

2. Description of the Related Art Conventionally, in electronic equipment, the presence or absence and the position of a transported object are detected by using a photo interrupter or the like in which a light emitting element and a light receiving element are combined.

In particular, various types of electronic devices such as printers have been proposed in accordance with the type of recording head. In each type, basically, recording sheets stacked in a sheet feeding tray are fed. Recording head (for example, thermal head) is contacted with the recording paper wound on the platen roller via the roller, and after predetermined printing or recording is done, it is recorded on the discharge tray etc. via the discharge mechanism etc. The recording paper of is ejected.

An edge sensor as well as a jam sensor is arranged in the path of the above-mentioned paper feeding → recording → sheet discharging to monitor the passing state of the recording sheet in the process of recording or printing. There is.

[0005]

In the case of using a thermal head or the like as the magnetic head, a large amount of heat is stored, and forced air cooling is performed using a fan or the like so that the temperature of the thermal head does not rise.

Therefore, dust is also sucked into the printer by the fan. In particular, dust adheres to the lens surface of the optical sensor placed in the vicinity of the fan, and dust adheres to the recording paper that is being printed, which deteriorates the quality of the printed recording paper.

Further, no printer or the like has been proposed that automatically detects a state in which the function of the sensor cannot be guaranteed and automatically issues a warning to the user.

The present invention has been made to solve the above problems, and its purpose is to automatically notify the time required for maintenance of an optical sensor in an electronic device or the like incorporating the optical sensor. The present invention is intended to provide a dust detection device that can be used.

[0009]

As shown in FIG. 1, a dust detection device of the present invention has a sensor 1 arranged at a predetermined position of an electronic device and a high level output of the sensor 1. And a low level, and a control means 3 for determining that the calculation result of the high level and the low level has become a predetermined value or less, and an informing means 4 for displaying or sounding the determination result of the control means 3. It is equipped with.

[0010]

According to the dust detector of the present invention, when the optical sensor or the like is contaminated with dust, the output of the optical sensor is detected at the high level and the low level, the difference between these two levels is detected, and the difference is a predetermined level. When the value is less than the value, the user is informed that the optical sensor should perform maintenance, so that the dust detection device in which the time when the maintenance should be performed is immediately known can be obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a detailed description of an embodiment of the dust detection device of the present invention applied to a printer.

Before describing the hardware and software configurations of the present invention with reference to FIGS. 1 to 3, a specific configuration of the printer of the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 and FIG. 5 are side views and a plan view of the ribbon showing the operating states of the main operating points for explaining the paper feed → recording → paper discharge path (hereinafter referred to as the recording paper route) of the printer of this embodiment. It is a figure.

In FIG. 4, recording papers 26 are stacked in the paper feed tray 5 and are sequentially fed one by one into the recording paper route. A movable plate 6 is attached to the bottom of the paper feed tray 5 so as to be cantilevered, and the recording paper is placed on the movable plate 6.

By rotating the paper feed arm 7 counterclockwise, the front end of the paper feed arm 7 is inserted into this slit through a slit formed in the bottom plate of the paper feed tray 5 and cantilevered and held. The plate 6 can be moved upward.

A paper feed roller 8 is driven by a paper feed motor 9. The paper feed roller 8 includes a fixed roller 8A and a movable roller 8
The movable roller 8B is driven by the drive motor 9 so that the circumferential surface of the movable roller 8B can contact the circumferential surface of the fixed roller 8A.

Reference numeral 12 is a platen roller, and the pinch rollers 13 and 14 can contact the outer periphery of the platen roller. Fixed roller 8A and pinch roller 1
A guide plate 10 for guiding the recording paper is arranged between the three.

In the vicinity of the paper feed roller 8 of the guide plate 10, a jam sensor 11 for detecting the jamming state of the recording paper.
Is provided, and a cueing sensor 15 used when performing color printing on recording paper is provided near the pinch roller 13.
This sensor receives light from a light emitting element 16 such as an LED mounted on the left end side of the casing 17.

Reference numerals 18 and 19 are ribbon reels, and a ribbon 20 is wound and wound between both reels. As shown in FIG. 5, this ribbon 20 has a cue signal H.
After S, Y (yellow), M (magenta), C (shiyan) ...
Ink is repeatedly applied in sequence.

A thermal head 21 is provided at the rear of the ribbon 20.
Is movably provided, and the thermal head 21 is pressed on the recording paper wound around the platen roller 12 via the ribbon 20 to perform recording (printing).

A guide plate 23 for ejecting paper is disposed between the pinch roller 14 and the paper ejecting roller 22, and an edge sensor 24 for detecting the edge of the recording paper is provided near the guide plate 23. The recording sheets recorded via the are stacked on the discharge tray 25.

A fan motor 27 and the like for forcibly cooling the thermal head 21 by air are attached to the casing 17. For this purpose, the jam sensor 11, the cue sensor 15,
The dust sucked by the fan adheres to the lens portion of the light emitting element 16, the edge sensor 24 and the like, so that the function of each optical sensor cannot be guaranteed. Therefore, in this example, the quality of printed matter is stabilized by automatically detecting this and notifying the user to clean the sensor.

FIG. 1 is a system diagram of the dust detection device of this embodiment described above.
Shown in. Among the sensors described above in the figure, for example, a jam sensor will be described.

The analog signal from the sensor 1 is analog-
The data is supplied to a digital conversion circuit (hereinafter referred to as ADC) 2 and converted into digital data, and then a microcomputer (hereinafter referred to as C
(Referred to as PU). Of course, if the CPU 3 has an ADC port, the analog signal of the sensor 1 is supplied to the ADC port of the CPU 3.

The CPU 3 detects a change in the sensor potential from the data from the sensor 1 and supplies it to the notifying means 4 such as a display means and a sounding means to inform that the sensor 1 requires maintenance.

In this example, the high level (hereinafter referred to as the H level) and the low level (hereinafter referred to as the L level) of each sensor are input to the CPU 3 during the recording (printing) operation, and the CPU 3 outputs the H level.
When it is determined that the difference between the level and the L level is less than a certain value, it is determined that dust has adhered to the surface of the sensor, and an alarm is issued to the notification means.

A dust detecting device for a jam sensor will be described below with reference to FIGS. 2 and 3.

When the recording (printing) button of the printer is pressed as in the first step ST ₁ in FIG. 2, the CPU 3 causes the paper feed arm 7 to rotate counterclockwise and move the movable plate 6 upward. Make an action. At this time, since the recording paper 26 placed on the movable plate 6 is still on the paper feeding tray 5, the second paper
If the jam sensor 11 is a transmissive sensor as shown in step ST ₂ , an H-level analog signal is output, and this is taken into the CPU 3 via the ADC 2 in the third step ST ₃ .

In the next fourth step ST ₄ , as shown in FIG. 4, the recording paper 26 is sandwiched by the paper feed roller 8 composed of the fixed roller 8A and the movable roller 8B, and the front surface of the jam sensor 11 is guided along the guide plate 10. The output of the jam sensor 11 at this time is cut off and becomes L level.

At this time, the L level is transmitted to the CPU 3 through the ADC 2 in the fifth step ST ₅ .

In the sixth step ST ₆ , the CPU 3 determines whether the difference H-L = H ₁ or H ₂ between the H and L levels input in the _third and fifth steps ST ₃ and ST ₅ is smaller than a predetermined constant value. Check. When the difference H ₁ or H ₂ is NO larger than the fixed value, the jam sensor 11 is determined to be normal, and the process proceeds to the tenth step ST ₁₀ and ends.

When the printer is used for a long period of time, FIG.
As shown in A and B, the analog values H ₁ and H ₂ of the difference between the H level and the L level are gradually displaced. Therefore, when the difference between the H level and the L level becomes a certain value or less, the dust is detected by the jam sensor. It may be considered that the lens 11 is attached to the lens.

When the sixth step ST ₆ is YES, the notifying means 4 is notified that the maintenance is necessary as in the seventh step ST ₇ .

This informing method can display on a display means such as an LCD or give an alarm such as a buzzer.

Although only the H and L levels of the jam sensor have been described in the above-mentioned flow chart, the difference between the H and L levels of the edge sensor 24 is obtained at the same time.

In the eighth step ST ₈ , maintenance is further facilitated by displaying the type of each sensor thus checked, for example, the jam sensor 11 or the edge sensor 24 on the display means.

In the ninth step ST ₉ , the operation may be stopped.

According to the above-mentioned dust detection device of this example, not only the maintenance time is known before the dust adheres to the lens of the sensor and the control becomes uncontrollable, but which sensor is defective, and the maintenance becomes easier. .. Further, since the sensor is dirty, it is possible to perform maintenance on other parts by considering that the other parts are also dirty with dust.

Although the optical sensor arranged in the printer has been described in the above configuration, it is obvious that the dust detection device of the present invention can be used for an optical sensor used in other electronic equipment.

[0040]

According to the dust detection device of the present invention, the time when the sensor should be maintained is automatically detected, and the dirt of the sensor is wiped off to obtain a print paper of good print quality.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a dust detection device of the present invention.

FIG. 2 is a flow chart of the dust detection device of the present invention.

FIG. 3 is a detection level waveform diagram of the present invention.

FIG. 4 is a side view for explaining the operation of the printer used in the dust detection device of the present invention.

FIG. 5 is an explanatory diagram of a ribbon of a printer used in the dust detection device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 sensor 2 ADC 3 CPU 4 notification means 11 jam sensor 24 edge sensor 26 recording paper 27 fan motor

Claims (1)

[Claims] 1. A sensor arranged at a predetermined position of an electronic device, and detecting a high level and a low level of the output of the sensor,
It is characterized by comprising control means for judging that the calculation result of the high level and low level has become below a predetermined value, and an alarm means for displaying or sounding the judgment result of the control means. Dust detection device.