JPH05232895A - Controller for light emitting diode - Google Patents

Abstract

PURPOSE:To easily confirm the normal light emission of a light emitting diode(LED) by turning on the LED or making it flicker according to a display sequence which is previously set. CONSTITUTION:A three-color LED is used as the LED for displaying a power source 18e and controlled so as to turn on a green color in accordance with the turning-on of a power source when a photosensitive drum can be still used, to turn on an orange color in accordance with the turning-on of the power source when the life of the photosensitive drum is drawn to an end and to turn on a red color in accordance with the turning-on of the power source when the life of the photosensitive drum arrives at the end. Then, when a power source key 18a, a printing stop key 18c and a reset key 18d are simultaneously inputted under a state that the power source is turned off, the test processing of the LED is executed before a normal printing action is executed. That means when the LED 18e is turned on for a second, for example, switched so as to turn on the orange color and a second passes further, the LED 18e is switched so as to turn on a green color.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode control device used in an electronic device such as a printer which uses a light emitting diode (hereinafter abbreviated as LED) as a display for displaying the state of its own.

[0002]

2. Description of the Related Art For example, a laser printer irradiates a charged photoconductor with a laser beam based on information of print data from a laser scanner unit to expose the photoconductor, and electrostatically forms an electrostatic latent image on the photoconductor with toner. The image is developed, then the developed image is transferred to a sheet, and the image is further fixed to perform printing.

In this laser printer, a non-volatile storage element (for example, EEPRO) capable of reading and writing the number of printed sheets is used.
There is a system in which a cumulative count is made by M (electrically erasable programmable read only memory)), the life of the photoconductor is judged by the number of printed sheets, and the operator is notified.

As a means for notifying the life of the photosensitive member, an LED for power supply which is turned on by turning on a power switch
It is common to use a (light emitting diode). That is, when a three-color LED is used as the power source display LED and the life of the photoconductor is not reached (for example, the number of printed sheets is 0 to 9000).
When the power is turned on, the green light is turned on, and when the life of the photoconductor is approaching (the number of printed sheets is 9000 to 1000).
When the number of printed sheets is 0, the orange color is turned on in response to power-on, and when the photoconductor has reached the end of its life (10000 or more printed sheets), red is turned on in response to power-on. By doing so, the operator can know the life of the photoconductor from the light emission color of the LED for power supply when the power switch is turned on.

[0005]

However, it has not been possible to confirm whether or not the LED mounted on this type of electronic equipment normally works until the condition for lighting or blinking is satisfied.

In particular, in the case of the laser printer as described above, when the number of printed sheets reaches 9000, whether the emission color of the power source display LED really changes from green to orange, or the number of printed sheets reaches 10,000. Sometimes it takes too much time to check if the color changes to red, so care has been neglected, and it may not be possible to prevent the deterioration of printing quality due to the life of the photoconductor in advance.

Therefore, the present invention is intended to provide a light emitting diode control device capable of easily confirming that an LED mounted on an electronic device can normally emit light at any time and improving the reliability of the electronic device. is there.

[0008]

SUMMARY OF THE INVENTION The present invention is a light emitting diode control device for controlling the light emission of an LED which is mounted on an electronic device and which lights or blinks according to the state of the electronic device, and selects a test mode of the LED. It is provided with a test mode selection means and a test operation control means for lighting or blinking the LED according to a preset display sequence when the test mode is selected by the selection means.

[0009]

According to the present invention having such a structure, when the test mode selecting means selects the test mode of the LED, the test operation control means causes the LED to be turned on or blinking in accordance with a preset display sequence. .. Therefore, just by selecting this test mode,
It can be confirmed that the LED mounted on the electronic device can normally emit light.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a laser printer will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a laser printer, in which a photosensitive drum 2 is disposed at a substantially central portion of a housing 1 in which one end is axially supported and the other end is vertically separable. The photosensitive drum 2 is driven to rotate in one direction by a drive motor 3, that is, in the clockwise direction in the figure, and the photosensitive layer on the surface of the photosensitive drum 2 is surrounded by the electrophotographic process around the photosensitive drum 2. A charger 4 for uniformly charging the toner, a laser scanner unit 5 for irradiating the photosensitive layer charged by the charger 4 with a laser beam based on image information to form an electrostatic latent image, and a laser scanner unit 5 formed on the photosensitive layer. A developing device 6 for adhering toner to the electrostatic latent image to develop it, a transfer charger 7 for transferring the image developed by the developing device 6 to a transfer paper conveyed through a conveying path, and a cleaning for removing toner from the photosensitive drum 2. A device 8 and a discharging lamp 9 for discharging the photosensitive drum 2 are sequentially arranged.

The transfer charger 7 is located below the photosensitive drum 2, and a pickup roller 11 is operated from a paper feed cassette 10 provided on one side of the housing 1 toward the transfer charger 7. The transfer paper is conveyed one by one at a predetermined timing.

The transferred transfer paper is a transfer charger 7.
Thus, the toner image on the photoconductor drum 2 is transferred, then the charge is removed by the charge removing unit 12, and further fixed by the fixing device 13. Then, the fixed transfer sheet is ejected by the ejection roller 1
It is configured to be discharged to the outside of the housing by 4, 14. Incidentally, the drive motor 3 serves as a drive source for the transfer drum transport mechanism as well as a drive source for the photosensitive drum 2.

Further, inside the casing 1, a fan 15 for discharging internal heat to the outside, a power supply device 16, and a cover open switch 17 for detecting when the casing 1 is vertically separated and turning off the power. Etc. are provided.

Further, on the upper surface of the casing 1, as shown in FIG. 3, a power key 18a for switching the power on and off,
Print start key 18 for instructing the central processing unit to start printing
b, a print stop key 18c for instructing the central processing unit to stop printing, a reset key 18d for instructing the central processing unit to cancel the error state, and an LED (light emission) for power supply that lights up when the power is turned on. Diode) 18e
And an operation panel 18 including a liquid crystal display 18f for displaying various kinds of error information such as the location of a paper jam error.

Here, a three-color LED is used as the power source display LED 18e, and when the life of the photosensitive drum 2 is not reached (for example, the number of printed sheets is 0 to 9000), the green light is turned on in response to the power-on, and the light is exposed. When the life of the body drum 2 is approaching (the number of printed sheets is 9,000 to 10,000), the orange color is turned on in response to the power-on, and when the life of the photosensitive drum 2 is reached (the number of printed sheets is 10,000 or more). It is controlled to turn on the red color when the power is turned on.

FIG. 2 is a block diagram showing a circuit configuration of the laser printer, and reference numeral 21 is a CPU constituting a main body of the control unit.
(Central processing unit), 22 is an interface for receiving print data and the like sent from a host device via a transmission path, and 23 is a ROM (Read Only) for storing program data for operating the CPU 21. Memory), 24 is a RAM (random access memory) in which a memory area for storing print data received by the interface 22 is stored in page units, and 25 is an I / O port for controlling input / output of information. .. These are connected to each other via a data bus 26.

The I / O port 25 is connected to the motor 3
A motor driver 27 for driving the laser scanner unit 5, the laser scanner unit 5, the charger 4 and the transfer charger 7.
High-voltage power supply 28 for supplying a high voltage to the developing device 6, the developing device 6, EE
Various sensor circuits 30 incorporating a PROM (Electrically Erasable Programmable ROM) for accumulatively counting the number of printed sheets, various sensor circuits 30 for taking in detection signals from various sensors such as a paper empty sensor, a toner empty sensor, and a jam sensor, and the operation panel. 18 etc. are connected respectively.

The + 5V power source from the DC power source 16 is supplied to the CPU 21, the interface 22, the ROM 23,
Connected to RAM24 and I / O port 25 respectively, +2
A 4V power source is connected to the motor driver 27, the laser scanner unit 5, the high voltage power source 28, and the fan 15 via the cover open switch 17, respectively.

However, the CPU 21 is program-controlled to execute the control shown in FIG. 4 when the power is turned on by turning on the power key 18a on the operation panel 18.

That is, the RAM 24 responds to power-on.
After executing various initialization processes such as clearing the above, resetting the I / O port 25, etc., it is determined whether or not the reset key 18d and the print stop key 18c of the operation panel 18 are both input. Then, the reset key 18d
If neither the print stop key 18c has been input, a normal main routine is entered to control execution of the print operation.

On the other hand, when both the reset key 18d and the print stop key 18c are input (test mode selection means), the LED test mote is selected, and therefore the LED test process described later is performed. After the execution, the main routine is entered to control the execution of the printing operation.

FIG. 5 is a flow chart specifically showing the LED test process. When the LED test process is started, first, the power source display LED 18e is turned on in red.
When 1 second elapses in this state, the power source display LED 1
Switch 8e to orange lighting. After another second,
The power source display LED 18e is switched to green lighting. In this state, the LED test process is terminated after waiting 1 second. (Test operation control means)

In the laser printer of this embodiment having the above-described structure, it is possible to confirm whether the power source display LED 18 operates normally and whether the life of the photosensitive drum 2 can be reliably detected.

That is, with the power off, the power key 18
a, the print stop key 18c, and the reset key 18d are simultaneously pressed. Then, the above-described LED test process is executed before the normal printing operation is performed. Then, first, the power source display LED 18 lights in red for 1 second. Next, the power supply display LED 18 is switched to orange lighting. Then, when one second elapses again, the power source display LED 18 is switched to green lighting. Here, when there is an abnormality in the power supply display LED 18, the display state is not switched in the display sequence described above, so the power supply display LED 1
It can be confirmed that 8 is not operating normally.

When the power source display LED 18 is normal, a normal printing operation starts. At this time, the drum counter 29
When the number of printed sheets counted by is less than 9000, the photoconductor drum 2 has not reached the end of its life, and therefore the power source display LED 18 is kept in the green lighting state. On the other hand, when the number of printed sheets exceeds 9,000, the life of the photosensitive drum 2 is approaching, and therefore the power source display LED 18 is switched to orange lighting. Furthermore, the number of printed sheets is 1000
When the number of sheets exceeds 0, the photoconductor drum 2 has reached the end of its life, so that the red light is switched on.

As described above, according to the present embodiment, the power-on state and the possible lighting state of the power source display LED 18e for notifying the life of the photosensitive drum 2 can be changed when the power source is turned on even if the lighting condition is not satisfied. Power key 18a
This can be confirmed by a simple operation of pressing the print stop key 18c and the reset key 18d at the same time when the key is input.

Therefore, the LED for indicating the power source can be easily used at any time.
Since the possible lighting state of 18e can be confirmed, it is possible to prevent a problem in which the life of the photoconductor drum 2 cannot be grasped due to an abnormality in the power source display LED 18e and the print quality is degraded.

In the above embodiment, the case where only the power source display LED is tested has been shown. However, if there is another LED that lights up or blinks according to the state of the laser printer, those LEDs are turned on. Alternatively, the LED test process may be executed by setting the display sequence so as to sequentially check the blinking state.

In the above embodiment, the print stop key 1 is turned on when the power is turned on as a means for selecting the LED test mode.
Although the means for simultaneously inputting the key 8c and the reset key 18d has been shown, the present invention is not limited to this, and the LED test mode may be executed by another key combination operation. Further, the present invention is not limited to the case where the power is turned on. For example, a specific switch for selecting the LED test mode is provided inside the housing and the LED test mode is executed when the switch is turned on while the power is turned on. May be.

Further, it goes without saying that the present invention is not limited to laser printers, but can be applied to various electronic devices equipped with LEDs such as serial printers and word processors.

[0032]

As described above in detail, according to the present invention, it is possible to easily confirm that the LED mounted on the electronic device can normally emit light at any time, and the reliability of the electronic device can be improved. A control device can be provided.

[Brief description of drawings]

FIG. 1 is a structural diagram of a laser printer that is an embodiment to which the present invention is applied.

FIG. 2 is a block diagram showing a control circuit configuration of the embodiment.

FIG. 3 is a plan view showing a configuration of an operation panel according to the embodiment.

FIG. 4 is a flowchart showing a power-on process of the CPU in the embodiment.

FIG. 5 is a flowchart specifically showing the LED test process of FIG.

[Explanation of symbols]

18a ... power key, 18b ... printing start key, 18c ... printing stop key, 18d ... reset key, 18e ... power source display LED (light emitting diode), 21 ... CPU (central processing unit).

Claims (1)

[Claims] 1. A light emitting diode control device for controlling light emission of a light emitting diode which is mounted on an electronic device and is turned on or blinks according to a state of the electronic device, and a test mode selecting means for selecting a test mode of the light emitting diode. A light emitting diode control device comprising: a test operation means for lighting or blinking the light emitting diode according to a preset display sequence when a test mode is selected by the selecting means.