JPS6064871A - Optical printer - Google Patents

Abstract

PURPOSE:To obtain a fresh image and to reduce the power by preventing the afterlight to a photosensitive member in the exposure stopping time of individual LED fored on the LED array by modulating a picture signal with high frequency. CONSTITUTION:A high frequency signal f1 generated from a high frequency oscillator 305 is inputted to the other input terminals of gate circuits G1-GN of a controller 301. Accordingly, an image signal from a data selector S inputted to one input terminals of the circuits G1-GN is modulated by a high frequency signal f1, outputted from the circuits G1-GN, and inputted to LEDL1-LN of an LED array 200 through transistors Q1-QN of an LED driver 300 and current controlling resistors R1-RN. When an exposure is started at the exposure starting time t1, the surface potential of the photosensitive member varies between a dark level VD and a bright level VL by an LED which is intermittently fired in response to a picture signal modulated by high frequency. Then, the rise of the surface potential at the exposure stopping time t2 is accelerated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical printer device that uses a light-emitting rod array as a light source.

[Prior art]

Conventionally, this type of device rewrites a line of image data into an LED array to form a latent image.

However, when the individual LEDs formed in the LFiD array are switched from ON to OFF'F, an afterglow occurs on the photoreceptor, making the printed image unclear.

[Purpose of the invention]

The present invention has been made by focusing on the above-mentioned drawbacks, and includes an optical printer device that forms an image on a photoreceptor by lighting up the entire light-emitting element array in response to an image signal. By modulating the photoreceptor, it is possible to prevent afterglow from remaining on the photoreceptor during the exposure stop time of each LED formed in the LED array, thereby obtaining a clear image and reducing power consumption. The purpose of this invention is to obtain an optical printer device that can perform the following steps.

[Explanation of Examples]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

FIG. 1 is a view showing the schematic configuration of an optical printer device. In the figure, +00 is a photoconductor drum whose surface is formed of a photoconductor, which rotates in the direction of the arrow in the figure, and whose surface is charged by a charger 101. The photosensitive drum 100 is irradiated with light from the printer head +02 to form a latent image. Thereafter, toner is applied to this latent image by a developing device 103 to make it visible.

On the other hand, the transfer paper stored in the sumo wrestler drum 04 is fed by the paper feed roller /'+05, and then the leading edge of the visible image formed on the photoreceptor drum +00 by the registration roller ]06. , and are fed at a timing such that the tip ZM of the transfer paper coincides with the tip ZM of the transfer paper. The toner adhering to the photosensitive drum 100 is transferred onto a transfer paper by a transfer device 101 and then fixed by a fixing device 108. The transfer paper on which the toner has been fixed is discharged to the tray 109 as a print output. Also, the photoreceptor drum +0 after the transfer is completed.
0 has its surface charge removed by the eraser 1!0, and is further cleaned by removing residual toner by the cleaner 111, returning to its original state.

Figure 2 shows L forming a large number of L E D L, ~LN.
2 is an enlarged plan view showing the Jg and physical configuration of the ED array 200. FIG. In the figure, 201 is a substrate wafer, which is generally made of GaAs (gallium arsenide). Reference numeral 202 denotes an electrode, and 203 denotes a light emitting section constructed by performing a PN junction between the substrate wafer 201 and 8i02 (silicon peroxide), which are arranged on the substrate wafer 201 at a high density of about 16 elements per 1 mr+. There is. Therefore, this L E
The density of D L+ to LN is directly connected to resolution. Note that FIG. 3 shows the light intensity in the light emitting part 203 and the non-light emitting part of the LIDD array 200. This LED array 200 serves as a light source for irradiating the photoreceptor drum +00 with the blink head 102 shown in FIG.
The rod lens array 204 is placed near the photoreceptor drum 100, or as shown in FIG. It is designed to form an image. Therefore, the photosensitive drum 100 is irradiated with light from the LED array ZOO to form a latent image, and a print is sent out through the series of copying operations described above.

FIG. 5 is a block diagram of the optical printer, and FIG. 6 is a circuit diagram showing each block in more detail. In FIG. 5 and FIG. 6, the LED LI to L
In the LED array 00 having N, each LED
Transistor 91 for driving L, ~LN~
qq and current control resistor R]~RN are connected,
The LED driver 300 is composed of current control resistors R1 to RN and transistors Q1 to QN. In this case, the above 1i E D L l-L
Flow to N in the J direction 1'jT.

The current is 10-30 (mA) and the control resistance R.

~RN may be set so that this amount of current flows. Moreover, E is a 1i source that drives the L E D L 1 to LN. G1~GNi, 1: L E I)
A gate circuit that controls the lighting of L l to LN, and S is a data selector that outputs an image signal and distributes it to LEDL+ to LN depending on the output D:r5 of S1 to SN, and the data selector S and the gate circuit G, - Controlled by GN: 31+30+. 302 is an oscillation circuit that generates a pulse fo (see Fig. 7) using the crystal lifter After being stored in the memory unit 304, the transfer speed is converted to an LED printer writing speed and then manually inputted to the data selector S.

Then, the data selector S sends one serial song manually, and the addressing outputs J'll Sl.
-SN is then manually inputted to one input n1 of the gate circuits G and -GN. (See Figure 7 1iQ)
Reference numeral 305 denotes a high frequency generating circuit which generates a high frequency signal No. 18 f1 using two crystal oscillators, and this high frequency signal +5f1 is input 11 to the other input terminals of the gate circuits 01 to GN.

Therefore, both signals input to one input terminal of the gate circuit G]~GN are changed at high frequency by the high frequency signal L as shown in FIG.
After output from 1 to GN, transistors Q1 to QNj
? and current control resistors R1 to RN.
L L N is full of human power.

FIG. 8 is a diagram showing changes in surface potential when the surface potential is charged by the charger 101 and exposed to light after dark decay over a predetermined period of time. Signal °
This shows the case where -re'C is performed without modulating with high frequency,
In the same figure, fbl shows a case where exposure is performed by changing both signals at a high frequency. First, in the same figure (al), exposure start 1
13 minutes 1. When exposure starts at , the surface potential reaches the bright level vL.
It goes down to Then, when the exposure is stopped at the exposure stop time t2, the surface potential reaches the dark level VD Kid after a certain period of time. Therefore, at time t2, both signals are 01"F
However, the surface potential has not reached the dark level VDK. On the other hand, in the same figure (in bl, exposure start time t]
When exposure is started at , the surface potential changes between a dark level VD and a bright level 75 as the LED lights intermittently in response to a high-frequency modulated image signal. The rise of the surface potential at the exposure stop time t2 is (I) in the same figure.
This is faster than the case shown in . Note that the broken line portion in the figure indicates the same figure (al). Therefore, the photosensitive drum 10
The occurrence of afterglow on 0 is almost prevented. 1, due to the high frequency, no current flows through the LEDK during the time when it is OFF, so
Electric car] Low LK. In addition, as shown in (1)) of the same figure, the contrast H between the dark level VD and the bright level ■L
Although it is somewhat lower than the case shown in Figure 1 (al), this can be easily improved by increasing the amount of light.

〔Effect of the invention〕

As described above, the optical printer device 4 of the present invention forms an image on a photoreceptor by lighting a light emitting element array in response to both signals, and modulates the image signal with a high frequency. By doing this, the individual L Fi I) formed in the array
ED Exposure Stop" The rise of the surface potential of the photoreceptor in one hour becomes faster, preventing afterglow from occurring on the photoreceptor, and making it possible to form a bright image. When is it effective? 1. Since the I'i current does not flow through the ULED during the OFF period of the high-frequency modulated image signal, the power can be reduced accordingly.

[Brief explanation of drawings]

Figure 1 shows a schematic configuration of an optical printer device according to an embodiment of the present invention. Figure 2 is an enlarged plan view showing the principle configuration of an L E ■) array. Figure 3 is an enlarged plan view showing the basic configuration of an array. A diagram showing the light intensity of the light-emitting part and non-light-emitting part of the thing shown in Figure 4.
Figure &:t Enlarged explanatory 1110th view showing the Rondo lens array interposed between the LED D array and the photoreceptor, No. 5
The figure is a block diagram of what is shown in Figure 1, and Figure 6 is a 265
Each block shown in the figure is explained in more detail. 41[1] is the circuit diagram, -17 is a time chart of the signal in the one shown in Fig. 6, and Fig. 8 is a diagram showing the surface tiL of the photoreceptor drum. , the same figure (al shows the case where exposure is performed without modulating both signals with high frequency, and 1ffi (+)l shows the case where the image signal is modulated with high frequency +J, :l and 11・& light is performed. 100...1 & light drum, 200... light emitting element array, 300... L E I) driver, 301...
・Control unit, Gl-GN...gate circuit, S...data selector, 305...jFjJ frequency generator 4-pin circuit Figure 1 In+ Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] In an optical printer device that forms an image on a photoreceptor by lighting a light emitting element array according to an image signal, the IL! An optical printer device characterized by modulating the 41 Hakugo with high frequency.