JP2003312892A - Apparatus for detecting kind of paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform a paper kind detection while correcting the dispersion of output value of a sensor element by environmental temperature change with out enlarging the package of a sensor. <P>SOLUTION: This apparatus for detecting kinds of paper comprises a means for emitting light from the sensor; a means for A/D converting a signal inputted from the sensor; a D/A conversion means for setting a threshold based on the result of the A/D conversion means; a means for performing the threshold set according to any one of copy start key, power supply switch, optional elapsed time, and environmental temperature change; a means for storing the threshold set by the D/A conversion means; a means for comparing the signal inputted from the sensor with the threshold set by the D/A conversion means; and a means for determining the failure of the sensor according to the input value of the sensor and displaying it on a display part. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer, etc. equipped with paper type detection such as OHT detection, and more particularly to a paper type detection device for the same.

[0002]

2. Description of the Related Art Conventionally, a reflection type sensor or a light shielding type sensor is used for paper type detection such as OHT detection, and a type of sensor which has a built-in comparator or the like and converts an output signal into a digital signal for output, Alternatively, a type that outputs an analog signal without a built-in comparator or the like, or a type that uses a sensor paired with a light emitting side and a light receiving side to adjust the light emission amount and detection value of each sensor has been used.

[0003]

However, in the above-mentioned sensor structure, for example, a type having a built-in converter or the like has a high cost and a large package. Further, in a type that does not have a built-in comparator or the like, the output value is not stable due to variations in the characteristics of the sensor itself and variations due to environmental temperature changes, which is not practical. In addition, in the type that adjusts the light emission amount and detection value of each sensor on the light emitting side and the light receiving side, there is a problem in that the package of the sensor becomes large because the labor and adjustment means for individually adjusting in the production process are provided. It was

The present invention has been made in view of the above problems, and corrects variations in sensor output values due to sensor elements and the like and variations due to changes in environmental temperature without enlarging the sensor package. However, it is an object of the present invention to provide a paper type detection device capable of detecting the paper type.

[0005]

The present invention provides OH as one of the means for solving the above problems.
In a copying machine, printer, etc. equipped with paper type detection such as T detection, based on the results of the means for causing the sensor to emit light, the means for A / D converting the signal input from the sensor, and the A / D conversion means. A D / A conversion means for setting a threshold value, a means for setting the threshold value according to a copy start key, power-on, arbitrary elapsed time, change in environmental temperature, etc., and input from the sensor. And a threshold value set by the D / A conversion means, and a means for judging a sensor failure according to an input value of the sensor and displaying it on a display unit. It is possible to correct the variation in the sensor output value and to detect the paper type.

[0006] The above-mentioned structure will be summarized and shown below in (1) to (4).

(1) In a copying machine or a printer having a paper type detection such as OHT detection, means for causing a sensor to emit light, means for A / D converting a signal input from the sensor, and the A / D conversion D / A conversion means for setting a threshold value based on the result of the means, means for setting the threshold value each time the copy start key is pressed, a signal input from the sensor and the D / A It is provided with a means for comparing the threshold value set by the conversion means to detect the paper type, and a means for judging a sensor failure according to the input value of the sensor and displaying it on the display unit. Paper type detection device.

(2) In a copying machine or a printer having a paper type detection such as OHT detection, means for causing a sensor to emit light, means for A / D converting a signal input from the sensor, and A / D conversion D / A conversion means for setting a threshold value based on the result of the means, means for setting the threshold value after power is thrown, signal input from the sensor and the D / A conversion means A paper type characterized by including a means for comparing the threshold value with the detected paper type to detect the paper type, and a means for judging a sensor failure according to the input value of the sensor and displaying it on the display unit. Detection device.

(3) In a copying machine, a printer, or the like equipped with paper type detection such as OHT detection, means for causing a sensor to emit light, means for A / D converting a signal input from the sensor, and A / D conversion D / A conversion means for setting a threshold value based on the result of the means, means for setting the threshold value at every elapsed time or at any time, a signal input from the sensor and the D And a means for comparing the threshold value set by the A / A conversion means to detect the paper type, and a means for judging a sensor failure according to the input value of the sensor and displaying it on the display unit. Paper type detection device characterized by.

(4) In a copying machine, a printer or the like having a paper type detection such as OHT detection, a means for causing a sensor to emit light, a means for A / D converting a signal input from the sensor, and the A / D conversion. D / A conversion means for setting a threshold value based on the result of the means, means for setting the threshold value according to a change in environmental temperature, a signal input from the sensor, and the D / A conversion A means for detecting a paper type by comparing with a threshold value set by means, and means for judging a sensor failure according to an input value of the sensor and displaying it on a display unit. Paper type detection device.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on the embodiments shown in the drawings.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment) FIG. 1 and subsequent drawings are for explaining one embodiment of the present invention, in which the control of an analog signal input by using a reflection type sensor is shown.
The operation will be described below according to the specific operation.

First, the structure of a 4-drum type copying machine will be described as an example.

In FIG. 10, reference numeral 317 is a yellow image forming portion, 318 is a magenta image forming portion, 319 is a cyan image forming portion, and 320 is a black image forming portion. However, the description of other image forming units will be omitted.

In the yellow image forming section 317, 34
A photosensitive drum 2 has a latent image formed on its surface by light from the LED array 210. A primary charger 321 charges the surface of the photosensitive drum 342 to a predetermined potential,
Prepare for latent image formation. A developing unit 322 develops the latent image on the photosensitive drum 342 to form a toner image. The developing device 322 includes a sleeve 345 for applying a developing bias and developing. A transfer charger 323 discharges from the back surface of the transfer belt 333 to transfer the toner image on the photosensitive drum 342 to a recording paper or the like on the transfer belt 333. In this embodiment, since the transfer efficiency is good, the cleaner portion is not arranged, but it is known that the cleaner portion can be mounted without any problem.

Next, a procedure for forming an image on a recording paper or the like will be described. The recording sheets and the like stored in the cassettes 340 and 341 are supplied onto the transfer belt 333 by the sheet feeding rollers 336 and 337 one by one by the pickup rollers 338 and 339. At this time, the sensor 901 is installed on the path along which the recording paper is conveyed, and the sensor 901 is turned on each time the recording paper passes or during the copying operation to determine the type of the recording paper. The fed recording paper is adsorbed by the electrostatic charger 346.
Is charged with. Reference numeral 348 denotes a transfer belt roller, which drives the transfer belt 333 and charges the recording paper or the like in combination with the adsorption charger 346 so that the transfer belt 333 adsorbs the recording paper or the like. A paper edge sensor 347 detects the edge of recording paper or the like on the transfer belt 333. The detection signal of the paper leading edge sensor 347 is sent from the printer section to the color reader section and is used as a sub-scanning synchronization signal when sending a video signal from the color reader section to the printer section.

After that, the recording paper or the like is conveyed by the transfer belt 333, and Y is transferred to the image forming units 317 to 320.
A toner image is formed on the surface in the order of MCK. The recording paper or the like that has passed through the black image forming unit 320 is separated from the transfer belt 333 in order to be easily separated.
After the charge is removed at 9, the transfer belt 333 is separated.
Reference numeral 350 denotes a peeling charger, which prevents image disturbance due to peeling discharge when the recording paper or the like is separated from the transfer belt 333. The separated recording paper or the like has a pre-fixing charger 351 or 3 in order to supplement the toner suction force and prevent image disturbance.
After being charged by 52, the toner image is thermally fixed by the fixing device 334 and then discharged to the discharge tray 335.

Here, when the copy start key 906 in FIG. 1 is pressed, the sensor 901 emits light in response to an ON signal, and the reflected light is output as an analog signal to the A / D circuit 902 and the comparator 905. Based on the analog signal input to the A / D circuit 902, the CPU 903 determines that the D / A circuit 90
4 is used to set the threshold value of the comparator 905. In the comparator 905, the analog signal from the sensor 901 and the D / A
By comparing the threshold values set by the circuit 904,
Judge whether it is HT or paper.

Next, the present invention will be described with reference to the flowchart of FIG. When the copy start key 906 is pressed in the step (hereinafter referred to as S) 100, the sensor 901 emits light in S101, the analog signal input is A / D converted in S102, and is input to the CPU 903 in S103. It In S104, the CPU 903 determines whether or not the output value of the sensor 901 is the failure level of the sensor 901. If not abnormal, the threshold value of the comparator 905 is calculated and the control signal is D / A converted in S105. D in S105
The A / A-converted signal is output to S106, and in S106, the sensor input value from S101 is compared with the threshold value from S105 to determine whether it is paper or OHT, and this operation ends. When it is determined that the sensor 901 is out of order in S104, the sensor abnormality is displayed on the display unit in S107, and the operation is finished. By performing such control, it is possible to detect the paper type by correcting the variation in the sensor output value each time copying is started.

A method of setting the threshold value will be specifically described with reference to FIG. First, the sensor 90 with nothing
1 is emitted and an analog output signal is obtained. This time, it is defined that 1.5V is input to make the explanation easy to understand. In addition, the output value does not change much in the state where nothing is present and the state where OHT is present, so that the values are equivalent here (state where nothing is present = state with OHT = 1.5V).

Next, it is assumed that the analog output signal when the sensor 901 emits light in the presence of paper is about 4.8V. 1.5V input to the A / D circuit 902 is 10
Converted by bit A / D circuit 132h (1023 × 1.5
V / 5V) is obtained. Based on this result, the CPU 903 considers that the threshold value of the comparator 905 is the input value × 2 times + 0.4, and sets 3.4 V thereof by the 8-bit D / A circuit (AD
h: 255 × 3.4V / 5V). Subsequently, the comparator 905 compares the analog signal 1.5V from the sensor 901 with the threshold value 3.4V set by the D / A circuit 904. Here, if the input signal from the sensor 901 is higher than 3.4 V, it is determined to be paper, and if it is low, it is determined to be OHT. Further, when the input value from the sensor is 2 V or more, the input value × 2 times + 0.
Since the threshold value becomes 4.4 V or more from 4 and the detection level is almost the same as that of paper, it is determined that the sensor is defective (sensitivity over), and that fact is displayed on the display unit.

Therefore, when the copying operation is started, if the sensor output is 1V, it is judged as OHT and 4.8.
If it is about V, it is determined to be paper. In this example, the threshold value is set to the input value × 2 times + 0.4V, but it goes without saying that the setting condition will change depending on the examination.

(Other Embodiments) The details of the present invention will be described based on the second embodiment shown in FIG.

In FIG. 3, when the power switch 907 is turned on, the sensor 901 emits light in response to an ON signal, and the reflected light is used as an analog signal for the A / D circuit 902 and the comparator 905.
Output to. Based on the analog signal input to the A / D circuit 902, the CPU 903 uses the D / A circuit 904 to set the threshold value of the comparator 905. Also, the memory 910
Backup the threshold value, and next time the power switch 90
The data is saved until the time of inputting 7. The comparator 905 compares the analog signal from the sensor 901 with the threshold value set by the D / A circuit 904 to determine whether it is OHT or paper.

Next, the present invention will be described with reference to the flowchart of FIG. When the power switch 907 is turned on in step S200, the sensor 901 emits light in step S201, and the input analog signal is A / D converted in step S202.
Is input to the CPU 903. CPU9 in S204
03 determines whether or not the output value of the sensor 901 is the failure level of the sensor 901, and if it is not abnormal, the threshold value of the comparator 905 is calculated in S205 and the control signal is D / A.
Convert. In S208, the threshold value set in S205 is backed up in the memory 910. Then, S205
The signal D / A converted by is output to S206 and S20
In step 6, the sensor input value from S201 and the threshold value from S205 are compared to determine whether it is paper or OHT, and this operation is ended. If it is determined in S204 that the sensor 901 is out of order, a sensor abnormality is displayed on the display unit in S207,
This operation ends. By performing such control, it is possible to detect the paper type by correcting the variation in the sensor output value each time the power is turned on.

(Other Embodiment 2) The details of the present invention will be described based on the third embodiment shown in FIG.

In FIG. 5, for example, the threshold setting timing is notified to the CPU 903 every arbitrary elapsed time such as 3 hours, 6 hours, 9 hours after the power of the timer 908 is turned on, and the sensor is set at the threshold setting timing. 901
Emits light in response to an ON signal from the CPU 903, and outputs the reflected light as an analog signal to the A / D circuit 902 and the comparator 905. Based on the analog signal input to the A / D circuit 902, the CPU 903 uses the D / A circuit 904 to set the threshold value of the comparator 905. The threshold value is backed up in the memory 910, and the data is saved until the next timing. The comparator 905 compares the analog signal from the sensor 901 with the threshold value set by the D / A circuit 904 to determine whether it is OHT or paper.

Next, the present invention will be described with reference to the flowchart of FIG. When the timer 908 reaches the set elapsed time in S300, the sensor 901 emits light in S301,
In step S302, the input analog signal is A / D converted and is input to the CPU 903 in step S303. S304
Then, the CPU 903 determines that the output value of the sensor 901 is the sensor 90
It is judged whether or not the failure level is 1, and if not abnormal, S3
At 05, the threshold value of the comparator 905 is calculated, and the control signal thereof is D / A converted. In S308, the threshold value set in S305 is backed up in the memory 910. The signal D / A converted in S305 is output to S306, and in S306, the sensor input value from S301 and S3 are input.
By comparing with the threshold value from 05, it is judged whether it is paper or OHT, and this operation is ended. When it is determined that the sensor is faulty in S304, the sensor abnormality is displayed on the display unit in S307, and the operation is finished. By performing such control, it is possible to correct the variation of the sensor output value due to the environmental temperature change at every arbitrary time and detect the paper type.

(Other Embodiment 3) Details of the present invention will be described based on a third embodiment shown in FIG.

In FIG. 7, for example, the environment sensor 909 is 1
Each time the temperature reaches a specific temperature such as 0 °, 20 °, 30 °, etc., the CPU 903 is notified of the threshold setting timing, and at the threshold setting timing, the sensor 901 causes the CPU 9
It emits light in response to an ON signal from 03, and outputs the reflected light as an analog signal to the A / D circuit 902 and the comparator 905.
C based on the analog signal input to the A / D circuit 902
The PU 903 uses the D / A circuit 904 to set the threshold value of the comparator 905. Further, the memory 910 backs up the threshold value, and the data is stored until the environmental temperature changes to an arbitrary temperature. In the comparator 905, the sensor 901
By comparing the analog signal from the and the threshold value set by the D / A circuit 904, it is determined whether it is OHT or paper.

Next, the present invention will be described with reference to the flowchart of FIG. When the environment sensor 909 reaches an arbitrary temperature in S400, the sensor 901 emits light in S401, and S
In step 402, the input analog signal is A / D converted,
It is input to the CPU 903 in S403. In S404, the CPU 903 determines whether or not the output value of the sensor 901 is at the failure level of the sensor 901, and if not abnormal, S405.
At, the threshold value of the comparator 905 is calculated and the control signal is D / A converted. In S408, the threshold value set in S405 is backed up in the memory 910. And
The signal D / A converted in S405 is output to S406, and in S406, the sensor input value from S401 and S40 are input.
By comparing with the threshold value from 5, it is judged whether it is paper or OHT, and this operation is ended. When it is determined in S404 that the sensor 901 is out of order, a sensor abnormality is displayed on the display unit in S407, and the operation ends. By performing such control, it is possible to detect the paper type by correcting the variation of the sensor output value due to the environmental temperature change for each arbitrary temperature.

[0032]

As described above, according to the present invention, the variation of the sensor output value due to the sensor element or the variation due to the change of the environmental temperature is corrected without enlarging the package of the sensor, and Detection can be enabled.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention.

FIG. 2 is a flowchart showing a first embodiment of the present invention.

FIG. 3 is a diagram illustrating a second embodiment of the present invention.

FIG. 4 is a flowchart showing a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a third embodiment of the present invention.

FIG. 6 is a flowchart showing a third embodiment of the present invention.

FIG. 7 is a diagram for explaining the fourth embodiment of the present invention.

FIG. 8 is a flowchart showing a fourth embodiment of the present invention.

FIG. 9 is a diagram showing an example of the present invention.

FIG. 10 is a diagram showing a typical copying machine.

[Explanation of symbols]

210 LED array 317 Image forming unit (yellow) 318 Image forming unit (magenta) 319 Image forming unit (cyan) 320 Image forming unit (black) 321 Primary charger 322 Developing device 323 Transfer charger 333 transfer belt 334 Fixer 335 Output tray 336, 337 Paper feed roller 338,339 Pickup roller 340,341 cassettes 342 photosensitive drum 345 sleeve 346 Adsorption charger 347 Paper edge sensor 348 Transfer belt roller 349 Charge elimination charger 350 Peeling charger 351 and 352 Charger before fixing 901 sensor 902 A / D circuit 903 CPU 904 D / A circuit 905 comparator 906 Copy start key 907 power switch 908 timer 909 Environmental sensor 910 memory

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C061 AP04 AQ06 AR01 HK07 HN04                       HN15 HV02 HV32                 2G059 AA05 BB10 EE02 MM05 MM09                       MM10 MM14 MM19 NN02 NN08                       PP03 PP04                 2H027 DC02 DE02 EF06 GA30 GB07                       HA02 HA13 HA14                 3F048 AA01 AB01 BA06 BC03 CB03                       DB15 DC12

Claims (4)

[Claims] 1. A copying machine, a printer, or the like equipped with paper type detection such as OHT detection, means for causing a sensor to emit light, and means for A / D converting a signal input from the sensor.
D / A conversion means for setting a threshold value based on the result of the A / D conversion means, means for setting the threshold value each time the copy start key is pressed, and a signal input from the sensor And means for comparing the threshold value set by the D / A conversion means to detect the paper type, and means for judging the sensor failure according to the input value of the sensor and displaying it on the display unit. A paper type detection device comprising: 2. In a copying machine, a printer, or the like equipped with paper type detection such as OHT detection, means for causing a sensor to emit light, and means for A / D converting a signal input from the sensor.
D / A conversion means for setting a threshold value based on the result of the A / D conversion means, means for performing the threshold value setting after power-on, a signal input from the sensor and the D
And a means for comparing the threshold value set by the A / A conversion means to detect the paper type, and a means for judging a sensor failure according to the input value of the sensor and displaying it on the display unit. Paper type detection device characterized by. 3. A copying machine, a printer or the like having a paper type detection such as OHT detection, a means for causing a sensor to emit light, and a means for A / D converting a signal input from the sensor.
The D / A conversion means for setting the threshold value based on the result of the A / D conversion means, the means for setting the threshold value at an arbitrary elapsed time or at an arbitrary time, and the input from the sensor Means for comparing the output signal and the threshold value set by the D / A conversion means to detect the paper type, and the sensor failure is determined according to the input value of the sensor and displayed on the display unit. And a means for detecting the type of paper. 4. A copying machine, a printer or the like having a paper type detection such as OHT detection, a means for causing a sensor to emit light, and a means for A / D converting a signal input from the sensor.
A D / A conversion unit for setting a threshold value based on the result of the A / D conversion unit; a unit for setting the threshold value according to a change in environmental temperature; and a signal input from the sensor. A means for comparing the threshold value set by the D / A conversion means to detect the paper type, and a means for judging the sensor failure according to the input value of the sensor and displaying it on the display unit. A paper type detection device comprising: