JPH0356033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic recording device that converts an electrical image signal such as a computer output or a facsimile signal into a printed image using an electrophotographic copying process, and particularly relates to an electrostatic recording device that converts an electrical image signal such as a computer output or a facsimile signal into a printed image using an electrophotographic copying process. The present invention relates to an electrostatic recording device that converts into a synchronized optical signal and thereby obtains a hard copy.

Lasers and light emitting diode (LED) arrays are known as means for obtaining this type of optical signal, but when using lasers, mechanisms such as laser oscillators and polygon mirrors are relatively large. It is complex, expensive, and requires high precision in the optical system, making it difficult to make printers smaller and lower in cost.
Because it is difficult to make high-density LEDs as long as, say, an A4 sheet of paper, dozens of short chips are lined up in a row, but this requires high precision and the drive circuit is extremely complex. It had the disadvantage of becoming In addition, write heads that use LED arrays require a drive circuit.
A current is applied to the LED and the emission intensity is changed by controlling the current, but the drive circuit for controlling the current generates heat. Therefore, if the drive circuit is placed near the LED array in an attempt to make the write head more compact, the heat generated by the drive circuit will cause the temperature of the LED to change, causing the emission wavelength to vary depending on the sensitivity of the photoreceptor, resulting in a poor image quality. I can't do it. In other words, in a recording device that uses an LED array as a write head,
Placing the drive circuit near the LED array
It was virtually impossible.

In this regard, since the fluorescent tube is lit by applying a voltage to the light emitting segment, the drive circuit for the fluorescent tube does not generate heat. Therefore, it is possible to place a driving circuit near the fluorescent tube, but when a fluorescent tube is used as a write head of a recording device, a large number of light emitting segments are arranged densely, so it is necessary to simply drive the light emitting segments. If the circuit is placed near the head, the arrangement will not be efficient and it will be difficult to make the head itself more compact.

The present invention has been made in view of these points, and it is an object of the present invention to provide an inexpensive and compact electrostatic recording device, paying attention to the fact that a fluorescent display layer can be used as a means for optical writing. It is something.

Hereinafter, the present invention will be explained in detail using one example.

FIG. 1 is a schematic diagram showing an electrostatic recording device according to an embodiment of the present invention. 1 is a fluorescent tube, 2 is an IC as a drive circuit that controls blinking of the light emitting segment of the fluorescent tube 1 in response to an image signal, and 3 is a driving IC 2.
4 is a connector, 5 is a cable connected to the image signal generation circuit, and 6 is a support plate. Reference numeral 7 denotes a convergent light transmitting body array as an imaging optical system, which is provided opposite to the face glass of the fluorescent tube 1 and focuses the light emitted from the fluorescent tube 1 onto the surface of the photoreceptor drum 8. Around the photoreceptor drum 8, there is a charging charger 9 for charging the photoreceptor drum 8, a developing device 10, a transfer charger 12 for transferring the image on the photoreceptor drum to a recording paper 11, and a transfer charger 9 for transferring the image on the photoreceptor drum to a recording paper 11. A separation charger 13 that separates the photosensitive drum 8 and a cleaner 14 that removes residual toner from the photosensitive drum 8 are installed. 14 is a recording paper storage section, 15 is a fixing device, and the arrow represents the rotation direction of the photosensitive drum 8.

2 is a cross-sectional view of the vicinity of the fluorescent tube 1 in this embodiment as shown in FIG. 2. FIG. The fluorescent tube 1 includes an anode segment 18 formed on the glass substrate 16 by vacuum evaporation and a lead wire 19 in a vacuum container formed of a glass substrate 16 and a face glass 17.
It has a cathode filament 20 facing the anode segment 18, and has a grid 21 between the anode segment 18 and the cathode filament 20. The surface of the anode segment 18 is coated with a phosphor mainly composed of zinc oxide (ZnO), and the luminescent segment (hereinafter, the anode segment and the luminescent segment are referred to by the same symbol 18).
It is expressed as ). The luminescent segments are arranged in a line in the longitudinal direction of the fluorescent tube 1. Further, the lead wire 19 extends to the outside of the face glass 17, and is wire bonded 22 to the driving IC 2 disposed on the substrate 16 on which the fluorescent tube 1 is formed. The driving ICs 2 are disposed on both sides of the fluorescent tube 1 along the longitudinal direction of the fluorescent tube 1, and are connected to the clock interface circuit 3 via lead terminals 23. moreover,
A multilayer interference filter is formed on the face glass 17.

To explain the operation of this electrostatic recording device, a specified voltage is applied to the cathode filament in the fluorescent tube 1, and the cathode filament in the fluorescent tube 1 is heated to a state where thermoelectrons are emitted from its surface. I will give you. In this state, an image signal is inputted from an external image signal generation circuit via the cable 5, controlled via the clock interface circuit 3, and inputted to the driving IC 2. The driving IC 2 controls the image signal line by line and applies a positive voltage to the cathode filament to the light emitting segment 18 at a predetermined position. Cathode filament 2
The thermoelectrons generated at 0 are attracted by the grid 21 and accelerated, and collide with the light-emitting segment 18 to which positive electrons are applied. Fluorescence is emitted from the light-emitting segment 18 and current flows to the cathode filament 20. The luminance of the fluorescent tube 1 in this example is as follows: the grid 21 and the anode segment 1.
High brightness of about 2000 fL can be achieved by controlling the voltage between 8 and 8.

Light 24 from the light emitting segment 18 passes through the face glass 17, enters the light transmission array 7, and is focused on the surface of the photoreceptor drum 8. Since the light 24 emitted from this light emitting segment 18 has poor monochromaticity, the wavelength range is narrowed by the multilayer interference filter formed on the face glass 17 and transmitted.
Chromatic aberration caused by the transmitter array 7 is prevented.

On the other hand, the photosensitive drum 8 rotating in the direction of the arrow,
It is sequentially charged by the charging charger 9 and irradiated line by line with light 24 from the light emitting segment 18 to form an electrostatic latent image on the surface of the photosensitive drum 8, which is developed by the developing device 10 to form a toner image. do. Thereafter, the toner image is superimposed on the recording paper 11 sent from the recording paper storage section 14, and the transfer charger 12 applies an electric charge from the back side of the recording paper 11 to transfer the toner image from the surface of the photoreceptor drum 8 to the copy paper. 11 Transfer to the surface.
After that, the static electricity is removed by the separation charge 13, and the recording paper 1
1 is peeled off from the photoreceptor drum 8 and sent to a fixing device 15 to be fixed, and residual toner is removed from the surface of the photoreceptor drum 8 by a cleaner 14 in preparation for the next copying.

FIG. 3 is a schematic perspective view of the fluorescent tube 1 and the driving IC 2 in this embodiment. Light emitting segments 18 are arranged vertically in a vacuum container formed by a glass substrate 16 and a face glass 17, and driving ICs 2 are arranged vertically on both sides of the outside of the vacuum container on the glass substrate 16. are arranged in Although not shown in the figure, a cathode filament and a grid are provided within the vacuum vessel, as shown in FIG.

A circuit diagram of the fluorescent tube 1 and the driving IC 2 is shown in FIG. The lead wires 19 from the light emitting segments 18 arranged along the longitudinal direction of the fluorescent tube 1 are
Odd numbers are taken out towards the top of the diagram, and even numbers are taken out towards the bottom of the diagram. Drive IC2 (1
The odd-numbered driving ICs (indicated by dashed lines in the figure) each have a shift register, a latch circuit, a driver circuit, and a stabilizing resistor 25. controls a plurality of odd-numbered light emitting segments 18,
It is connected to the odd-numbered lead wires 19, and the even-numbered driving ICs (shown at the bottom of the figure) are similarly connected to the even-numbered lead wires 19. Cathode filament 20 is 20KHz
It is heated by electricity with a moderate AC power source. A DC voltage of +5V is applied to the grid 21.

Odd number data and even number data transmitted via the clock interface are determined by the timing of the odd clock signal generated by the clock interface.
Shift register (1)→(3)→…→(2n−1) in 2
The even data is also transmitted to the shift registers (2)→(4)→...→(2n) in the even numbered driving ICs 2 according to the timing of the even clock signal. When data is input to the shift register, the contents of the shift register are loaded into the latch circuit by the latch signal from the clock interface.
The driver circuit is activated by this captured data, and the driver circuit into which the data is input pulls up the corresponding light emitting segment 18 to a positive voltage from the cathode filament 20 using the stabilizing resistor 25, so that the light emitting segment 18 emits light. The light emitting segment 26 for leading end lighting and the light emitting segment 27 for rear end lighting are provided at both ends of the array of light emitting segments 18, and one light emitting segment 1
8 and is independently driven by an external drive circuit. Light-emitting segments 26, 2 for front and rear end lighting
Reference numeral 7 is used to remove charges from non-recording areas on both sides of the recording paper, and is always lit.

Here, an example of specific dimensions of the light emitting segments 18, 26, 27 is shown in FIG. The light emitting segment 18 has a width W ₁ of 70 μm and a height h of 80 μm, and the light emitting segments 26 and 27 for lighting the front and rear ends have a width W ₀ .
10 mm, the height h is 80 μm, and the intervals l between the light emitting segments are all 30 μm. In order to obtain a print width of A4 size (204.8 mm) using these light emitting segments, 2048 light emitting segments 18 are required. As shown in the figure, the lead wires are taken out alternately in opposite directions, and the odd-numbered lead wires and the even-numbered lead wires are connected to one driving IC in units of, for example, 16 lead wires.

FIG. 6 shows the arrangement of the ICs 2 on the substrate 16 on both sides of the fluorescent tube 1 in the longitudinal direction and the arrangement of the lead terminals. In the figure, K1, K
2,... is for driving connected to the odd numbered lead wire
Represents IC2, K1 is 1 of the odd numbered lead wire
The 16th to 16th wires are connected in such a way that K2 has 17th to 23rd wires. The same applies to the driving ICs 2, G1, G2, . . . connected to even-numbered lead wires. Then, 64 driving ICs 2 are arranged on each of the odd-numbered side and the even-numbered side, and each side controls 1024 light-emitting segments, and all the IC2s on both sides control 2048 light-emitting segments.

The signal input of the lead terminal will become clearer if you compare it with FIG. Here, the two ICs 2 each share one lead terminal for the drive power source (+5V) and one lead terminal for the ground (GND). That is, as shown in FIG. 7, for example, the odd-numbered ICs, K1 and K2, share the +5V lead terminal and the ground lead terminal, and K3 and K2 share the +5V lead terminal and the ground lead terminal.
Similarly, the lead terminals are shared with 4.

Details of one odd-numbered side driving IC 2 are shown in FIG. Shift register SR ₁ ~ SR ₁₆ , latch circuit LR ₁
~LR ₁₆ and driver transistor T _r1 ~
16 T _r16 are connected as shown in the figure.

Odd data signals from the data input terminals are sent to each shift register at the timing of the odd clock signal.
It is shifted in the order of SR ₁ → SR ₂ →...SR ₁₆ , and then shifted to the shift register of the next odd-numbered IC at the 17th odd-numbered clock signal. After a signal is transmitted to the shift register, a latch signal is input at a certain timing, and the contents of shift registers SR ₁ and SR ₁₆ are taken into latch circuits LR ₁ and LR ₁₆ , respectively.
Depending on the contents of the latch circuits LR ₁ and _.about.LR16 , it is determined whether the driver transistors T _r1 and _.about.Tr16 are operated. In FIG. 8, driver transistors T _r1 , ~T _r16 are latch circuits LR ₁ , ~
The output of LR ₁₆ goes low and the transistor
When the base voltages of T _r1 and ~ _Tr16 become low, the transistors T _r1 and ~ _Tr16 are turned on, and the light emitting segment emits light. In addition, the power supply is −25 to −
Approximately 45V is appropriate.

The same applies to the even number side drive IC.

FIG. 9 shows the pin arrangement of the driving IC 2.

1 is an IC on the odd number side, and 2 is an IC on the even number side. The pins on the signal input side are, from the left, power supply, latch signal, odd (or even) data input, GND, +5V, odd (or even) clock signal, and odd (or even) data output on both the odd and even sides. The pins on the output side are arranged in the order of P ₁ , P ₂ . . . P ₁₆ from the left. That is, the odd-numbered side IC and the even-numbered side IC have symmetrical pin arrangements.

FIG. 10 shows the drive IC 2, clock interface circuit 3, and external image signal generation circuit 28.
This shows the signal exchange between. When a line start signal is generated from the clock interface circuit 3 to the image signal generation circuit 28, data is sent from the image signal generation circuit 28 to the clock interface circuit 3 at the timing of the clock signal. Odd data (odd number data) is output from the clock interface circuit 3 at the timing of the odd clock signal.
is sent to the shift register of the odd-numbered side drive IC,
Even data (even-numbered data) is sent to the shift register of the even-numbered side driving IC at the timing of the even-numbered clock signal, and the latch signal to take in the signal from the shift register to the latch circuit drives both the odd-numbered side and the even-numbered side. is sent to the latch circuit of the IC.

FIG. 11 shows a specific example of the clock interface circuit 3. 13 flip-flops 3
0-1 to 30-13 are connected in series so that the set output of the previous stage becomes the input of the next stage, and a rectangular wave oscillation circuit or AC power supply 29 is connected to the input terminal of the flip-flop 30-1 of the front stage. A one-shot multivibrator 31 is connected to the set output _Q12 of the flip-flop 30-12 at the last stage. A one-shot multivibrator 34 is connected via an inverter 33 to the output side of a NAND gate 32 which receives the output _TA of this one-shot multivibrator 31 and the set output Q ₂ of the third-stage flip-flop 30-3. , the output T _B of this one-shot multivibrator 34 is connected to the inverter 3
5 through flip-flops 30-1, ~30-
13, and the output T _B of the one-shot multivibrator 34 is output via an inverter, and is used as an inverted latch signal and an inverted line start signal. Output of one-shot multivibrator 31
A NAND gate 37 is connected so that the inverted signal from the inverter 36 of T _A and the set output _Q1 of the second stage flip-flop 30-2 are input, and the output of this NAND gate 37 is used as an inverted clock signal. . Further, a NAND gate 39 is connected so as to input the inverted signal of the output of the NAND gate 37 by the inverter ₃₈ and the set output Q0 of the first stage flip-flop 30-1, and the inverted signal of the output of the NAND gate 39 by the inverter 40 is input. and the third stage flip-flop 30-3
A NAND gate 41 is connected so as to input the reset output ₂ of the NAND gate 41, and the output of this NAND gate 41 is used as an inverted odd clock signal. 30-3
A NAND gate 42 is connected so that the set output Q ₂ of the clock signal is input, and the output of this NAND gate 42 is an inverted even clock signal.

The data passes through two stages of inverters 43 and 44 and is output as odd data and even data.

The clock interface circuit 3 in FIG. 11 transmits and receives the signals in FIG. 10 as shown in FIGS. 12 and 13.
This will be explained using the waveform diagram in the figure. As an example, a case is assumed in which printing is performed in a recording area of 204.8 mm x 294.8 mm on A4 size recording paper using a fluorescent tube having a light emitting segment 18 having the dimensions shown in FIG.

In FIG. 12, when the line start signal sent from the clock interface circuit 3 to the image signal generation circuit 28 becomes low level, a clock signal is generated and data is sent at the timing of this clock signal. To finish recording on one sheet of A4 recording paper, 2948 line start signals are required, and each line start signal requires 2048 clock signals. Now, assuming that the recording paper feeding speed is 50 mm/sec, the period of the clock signal is approximately 0.9 μsec.

A more detailed explanation will be given in FIG. 13. _Q0 ,
Q ₁ , ~Q ₁₂ are flip-flops 30-
1, 30-2, to 30-13 set output signals,
T _A and T _B are the output signals of the one-shot multivibrators 31 and 34, respectively, and the signal T _B becomes a line start signal and a latch signal. When the line start signal (T _B ) goes low, data is transmitted from the image signal generation circuit to the clock interface circuit at the rising edge of the clock signal. The clock interface circuit is
This data is taken in at the falling timing of the clock signal and separated into odd and even data. The clock interface circuit outputs the odd number data and even number data to the shift register of the driving IC, and the odd number side shift register inputs the odd number data according to the timing of the odd number clock signal.
The even-numbered shift register receives even-numbered data at the timing of the even-numbered clock signal. 2048 clock signals are generated, the outputs T _A and T _B of the one-shot multivibrators 31 and 34 both go to high level, and then when the signal T _B goes to low level, the data input to the shift register is latched. The light-emitting segment emits light depending on the data content. Furthermore, since the signal T _B becomes low level, the data of the next row is transmitted from the image signal generation circuit to the clock interface circuit.
This operation is repeated 2948 times for A4 size recording.

In this example, the driving IC is provided on the same substrate as the light emitting segment and is integrated.
Maintenance and assembly become easier, and the recording head becomes smaller. Additionally, because the leads are formed on the same substrate as the light emitting segments, they can be processed simultaneously, thus reducing wire connection points and increasing manufacturing yield. Furthermore, the odd-numbered and even-numbered lead wires from the segments are pulled out in opposite directions of the segment row, and each group is divided into groups and controlled and driven separately, so that each segment group is driven. The circuit can be configured symmetrically with respect to the segment rows, which also has the effect of facilitating control.

As described above, the present invention is configured to form an electrostatic image on the surface of a photoreceptor by driving a fluorescent tube in which minute light emitting segments are arranged in a row.
Compared to electrostatic recording devices using lasers or light emitting diode arrays, it is possible to achieve a cheaper and more compact electrostatic recording device. Furthermore, since the drive circuit for driving the fluorescent tube is arranged on both sides of the fluorescent tube on the substrate, both the fluorescent tube and the drive circuit can be efficiently arranged on the substrate, which is effective in making the device more compact.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention;
Figure 2 is a cross-sectional view showing the vicinity of the fluorescent tube;
The figure is a schematic perspective view showing the fluorescent tube and driving IC in the present invention, and Figure 4 shows the fluorescent tube and driving IC.
A block circuit diagram showing the IC, Fig. 5 is a schematic plan view showing an example of the dimensions of the light emitting segment, Fig. 6 is a schematic plan view showing the arrangement of the drive IC and lead terminals, and Fig. 7 is a schematic plan view showing the arrangement of the drive IC and lead terminals. A block circuit diagram showing the connection state of the connected drive power lead terminal and ground lead terminal, Figure 8 shows one drive IC.
Figure 9 is a plan view showing the pin arrangement of the driving IC, Figure 10 is the driving IC,
FIG. 11 is a block circuit diagram showing the clock interface circuit;
FIG. 12 is a waveform diagram showing signals between the clock interface circuit and the image signal generation circuit;
The figure is a waveform diagram showing the signals shown in FIG. 10. 1... Fluorescent tube, 2... Drive IC, 3...
clock interface circuit, 7... optical transmission body array, 8... photosensitive drum, 9... charging charger, 10... developing device, 11... recording paper, 1
2... Transfer charger, 13... Separation charger, 14... Cleaner, 15... Fixing device, 16
... Substrate, 17 ... Face glass, 18 ... Light emitting segment, 19 ... Lead wire, 20 ... Cathode filament, 21 ... Grid, 22 ...
wire bonding.

Claims (1)

[Scope of Claims] 1. A fluorescence tube in which a plurality of minute light emitting segments are arranged in a line across the recording image width on the same substrate, and an imaging optical system that forms an image of light from the light emitting segments on the surface of a photoreceptor. , a plurality of drive circuits provided for each of the light emitting segments and applying a voltage to the light emitting segments according to an image signal to light the light emitting segments, and distributing the drive circuits to both sides of the fluorescent tube on the substrate. An electrostatic recording device characterized in that it is arranged at