JPH0516424A - Edge emitting EL head and edge emitting EL printer - Google Patents

Abstract

PURPOSE:To realize an end luminescent EL head which can be used for both a printer of a model turned to be power-saving and compact and light-weight, and a printer of a kind realizing high-speed and high-quality printing. CONSTITUTION:(m) common electrodes 32 are sequentially repeatedly connected to mXn end luminescent EL devices 19. nX(x) block electrodes 33 are connected to every m/x end luminescent EL devices 19. Accordingly, the ratio of the common drivers 35, 38 to the block drivers 36, 39 can be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge emitting EL which is one of an electrophotographic line head and a line printer.
The present invention relates to a head and an edge emitting EL printer.

[0002]

2. Description of the Related Art Currently, various printers have been put into practical use, and one of them is a line printer. For example, an electrophotographic line printer has a structure in which devices such as a charging device, a line head, and a developing device are closely arranged on the peripheral surface of a photosensitive drum, which is a latent image carrier located on a conveyance path of printing paper. The latent image is formed on the peripheral surface of the photosensitive drum, which is charged by the voltage applied by the charger, by the selective light emission of the light emitting elements connected to the line head, and the latent image is formed from the developing device. The toner supplied is developed and electrostatically transferred to printing paper. As a light emitting element of such a line head, an LED (Light) is generally used.
Emitting diode) and the like are used, but this has a problem that it is difficult to manufacture a line head having a uniform emission intensity because characteristics differences easily occur between mass-produced elements.

Therefore, at present, an edge emitting type E, which is also called as an edge emitter, is used as a light emitting element of a line head.
It is considered to use an L (Electro Luminescence) element. This edge emitting EL element is a device in which flat plate electrodes are formed on the upper and lower surfaces of a dielectric layer surrounding a thin film active layer made of zinc sulfide or the like containing an active element. As a result, extremely flat light with a luminescence intensity of about 100 times can be emitted from the end face of the active layer.

Therefore, as a conventional example of an edge emitting EL printer which is a line printer using such edge emitting EL elements, the apparatus disclosed by the applicant in Japanese Patent Laid-Open No. 2-274570 is shown in FIGS. 8 will be described. First, as illustrated in the block diagram of FIG. 5, the edge-emitting EL printer 1 is an external device such as a host computer.
A printer controller 2 for transferring print data input from (not shown) is connected to an interface 3, and the interface 3 is connected to first and second address counters 4 and 5 and a reference clock generator 6. A timing controller 8 is connected via the control circuit 7. Further, the interface 3 includes two RAs each having three states 9 to 12 connected to an input / output unit.
The RAM 1 is connected to an M (Random Access Memory) 13 and 14 via a first data processing circuit 15.
A control circuit 7 and the first and second address counters 4 and 5 are connected to 3 and 14 via a selector 16. Further, the RAMs 13 and 14 are connected to the second data processing circuit 17 to which the timing controller 8 is connected via the three states 11 and 12.

A drive IC in which the second data processing circuit 17 and the timing controller 8 are connected to each other.
(Integrated Circuit) 18 _{1 to} 18 q is a line head in which m × n edge emitting EL elements 19 are connected in an array, and n block electrodes 21 ₁ to 21 n are connected to the edge emitting EL head 20. The common driver array 22 to which the timing controller 8 is connected is connected to the edge emitting EL head 20 via m common electrodes 23 ₁ to 23 m. Here, each of the drive ICs 18 _{1 to} 18 q has a structure in which a shift register 24, a latch 25, an exclusive OR circuit 26, and a block driver array 27 are sequentially connected in parallel, and the components 24 to 26 are connected to the timing controller. 8 is connected.

More specifically, as shown in FIG. 6, the edge emitting EL printer 1 has m commons which are repeatedly and sequentially connected to the m × n edge emitting EL elements 19. The electrodes 23 ₁ to 23 m have m common drivers 28 ₁ to 28 ₁ built in the common driver array 22.
28 m are individually connected to the block driver array 27, and the n block electrodes 21 ₁ to 21 n are connected to each m m × n of the edge emitting EL elements 19 and are incorporated in the block driver array 27. N block drivers 29 ₁ ~
29n are individually connected.

Further, in this edge emitting EL printer 1, the edge emitting EL head 20 to which various circuits are connected as described above is a charger or a developing device (both not shown).
And the like are arranged in proximity to the peripheral surface of a photosensitive drum (not shown), and this photosensitive drum is located on the conveyance path of the printing paper (not shown).

With this arrangement, in the edge-emitting EL printer 1, the print data including the clock signal input from the printer controller 2 via the interface 3 has the first data processing circuit for each main scanning line. At 15, the data is compressed by processing such as rearrangement. Therefore,
This compressed print data is temporarily stored in one of the RAMs 13 and 14 during the printing time of one main scanning line, and at the same time, the print data temporarily stored in advance from the other RAM 14 and 13 is output at high speed.

A RAM for temporarily storing print data
The selection of 13 and 14 is performed by the selector 16 which operates according to the timing input from the printer controller 2 to the first address counter 4. RAM
The print data output from 14 and 13 is performed by the control circuit 7 and the second address counter 5 that operate in synchronization with the high-speed output reference clock signal issued from the reference clock generator 6.

Therefore, the output print signal for one main scanning line is reprocessed by the second data processing circuit 17 into a form suitable for printing, and is input in parallel to the drive ICs 18 ₁ to 18 q and held therein. It And these drive ICs
The block drivers 29 _{1 to} 29 n of 18 _{1 to} 18 q and the common drivers 28 _{1 to} 28 m are synchronously controlled by the timing controller 8, so that drive pulses of low voltage and high voltage are supplied to the block electrodes 21 _{1 to} 21 n and the common electrodes. 23 ₁ ~
23m from the edge emitting type E of the edge emitting type EL head 20
It is repeatedly output to the L element 19. At this time, by synchronously controlling these drive pulses, the voltage of the combined drive pulse is set to be equal to or higher than the threshold voltage of the edge emitting EL element 19 and the light emission or non-light emission is controlled.

Therefore, in this edge-emitting EL printer 1, for example, as illustrated in the time chart of FIG.
The above operation is performed four times during the printing time T ₀ of one main scanning line, and the edge emitting EL head 20 repeats line emission four times in the width of one main scanning line. This corresponds to the fact that the light emitted from the edge-emitting type EL element 19 is flat. By doing so, elongated pixel components in the main scanning direction are connected in the sub-scanning direction to form substantially square pixels. Can be formed. Therefore, such an edge-emitting type E
A selective light emitting operation of the L head 20 is performed on the peripheral surface of the photosensitive drum charged by the voltage applied by the charging device to form a latent image, and the latent image is developed with the toner supplied from the developing device to print paper. Electrostatically transferred to. Here, as shown in FIG. 8, the main scanning line printed as described above is beautiful because the edge-shaped serrated steps are minute, and moreover, a plurality of pixels are formed in one pixel area. Since the pixel constituent elements are connected in series, it is possible to prevent white spots from occurring in the pixel.

[0012]

With the above arrangement, the emission light of the edge-emitting EL element 19 is flattened to emit light in a single pixel region to form a pixel, thereby achieving good print quality. The edge emitting EL printer 1 can be obtained.

However, it is difficult to improve the printing speed of the edge-emitting EL printer 1 that repeats the light emitting operation to form an image, and there is a demand for this improvement. For example, it is conceivable that a photosensitive drum having a high photosensitivity is adopted to shorten the light emission time of the edge emitting EL element 19 once to improve the printing speed. However, the edge emitting EL element 19 has a characteristic Since it takes a long time to increase the emission brightness, it is not desirable to reduce the emission time.

The edge emitting EL printer 1 described above is also used.
In this case, since the m × n edge emitting EL elements 19 are matrix-driven by the m common drivers 28 and the n block drivers 29, the number of the common drivers 28 is reduced and the blocks are blocked. Driver 29
It is possible to improve the printing speed by increasing the number of prints. However, in this case, since the number of the block electrodes 21 and the block drivers 29 increases, the size reduction and weight reduction of the edge-emitting EL printer 1 and the productivity are hindered, and the power consumption increases.

In practice, in the edge-emitting EL printer 1 as described above, the number of common drivers 28 is increased and the number of block drivers 29 is reduced to realize power saving, and the common driver 28 is used. It is desired that the number of block drivers 29 be increased and the number of block drivers 29 be increased to improve the printing speed, depending on the type of equipment and the situation of use.

The present invention is to obtain an edge emitting EL head capable of realizing power saving, size reduction and weight reduction, printing speed increase and quality improvement.

Further, the present invention is to obtain an edge emitting EL printer in which power saving and speedup of printing operation can be selected as desired.

Further, the present invention provides an edge emitting EL printer which has a simple structure and realizes a high printing speed.

[0019]

The invention according to claim 1 is
M × n edge emitting EL elements are arranged in an array on the head substrate, and m common electrodes are sequentially and repeatedly connected to these edge emitting EL elements to form n × x block electrodes. Wiring was performed for every m / x of edge emitting EL devices.

According to a second aspect of the present invention, m common drivers are individually connected to m common electrodes of the edge emitting EL head, and n / x block electrodes are provided every n / x. Power-saving wiring to which the block driver is connected, and m / x common drivers are sequentially and repeatedly connected to m common electrodes of the edge emitting EL head, and n × x block electrodes are n × x blocks. A circuit switching means is provided for switching freely between the high-speed printed wiring to which the drivers are individually connected.

According to a third aspect of the present invention, m / x common drivers are sequentially and repeatedly connected to m common electrodes of the edge-emitting EL head, and n × x block electrodes are n × x block electrodes. I connected each block driver individually.

[0022]

It is possible to change the ratio of the number of common drivers and block drivers connected to the edge-emitting EL elements that are continuously provided on the head substrate so that power saving and high-speed printing can be selected.

[0023]

Embodiments of the present invention will be described with reference to FIGS. First, in this edge emitting EL head 30, as illustrated in FIG. 1A, m × n edge emitting EL elements 19 are continuously arranged in an array on a head substrate 31. M common electrodes 32 _{1 to} 32 m are sequentially and repeatedly connected to the edge emitting EL element 19 and n
The structure is such that xx block electrodes 33 _{1 to} 33n × x are connected for each n / x of the edge-emitting EL device 19. It should be noted that, as shown in the figure, the edge emitting EL of this embodiment is
In the head 30, m = 6 and x = 2 are set, and the following description will be given using these numerical values.

Then, the edge-emitting type E having the above-mentioned structure
The edge emitting EL printer 34 equipped with the L head 30 is
As shown in the figure (b), the six common electrodes have 6
Power-saving wiring 3 in which the common drivers 35 _{1 to} 35 ₆ are individually connected and n block drivers 36 ₁ to 36 n are connected for every 3 (= 6/2) of 2n block electrodes 3
7 and 3 (= 6/2) on the _six common electrodes 32 _{1 to} 32 ₆ of the edge emitting EL head 30 as illustrated in FIG.
The common drivers 38 _{1 to} 38 ₃ are sequentially and repeatedly connected and 2n for every 2n block electrodes 33 _{1 to} 33 ₂ n.
Circuit switching means for switchingably selecting one of the block drivers 39 _{1 to} 39 ₂ n and the high-speed printed wiring 40 to which the block drivers 39 _{1 to} 39 ₂ n are individually connected.
(Not shown) is provided.

The circuit switching means as described above can be implemented by, for example, a support mechanism which exchangeably supports the drive circuit boards 41, 42 on which the wirings 37, 40 as described above are formed in advance. The other circuit structure is the same as that of the edge emitting EL printer 1 described above.

Therefore, this edge emitting EL printer 34 is used.
An example of the specific structure of will be described with reference to FIG. First, in the edge-emitting EL printer 34, the charger 44 and the edge-emitting type E are provided at positions facing the peripheral surface of the photosensitive drum 43.
An L head 30, a developing device 45, a transfer device 46, and the like are sequentially arranged, and a transport path 48 for the printing paper 47 formed between the transfer device 46 and the photosensitive drum 43 is provided at one end of a main body housing 49. The attached paper feed cassette 50 communicates with a paper discharge section 51 on the upper surface of the main body housing 49.

With this structure, in the edge emitting EL printer 34, an electrostatic latent image is formed on the surface to be scanned of the photosensitive drum 43 charged by the corona discharge of the charger 44 by the optical scanning of the edge emitting EL head 30. The formed electrostatic latent image is developed by the charged toner supplied from the developing device 45 and transferred to the printing paper 47 conveyed in the conveying path 48 by the electric charge of the transfer device 46. When the edge-emitting EL head 30 performs optical scanning as described above, the edge-emitting EL printer 34, like the conventional edge-emitting EL printer 1, has each edge-emitting type for forming one pixel. By repeating the element light emission of the EL element 19, flat pixel constituent elements formed by one element light emission are continuously arranged to form a substantially square pixel.

Here, this edge emitting EL printer 34
Then, when the power saving wiring 37 as illustrated in FIG. 1B is selected by the switching operation of the circuit switching means, FIG.
As illustrated in the time chart of (a), the line emission performed during the time T ₁ is repeated during the time T ₀ , and the high speed printed wiring as illustrated in FIG. When 40 is selected, the line emission performed during time T ₁ ′ is repeated during time T ₀ ′, as illustrated in the time chart of FIG. 3B. At this time, the number of repetitions of this light emitting operation is the same for the power-saving wiring 37 and the high-speed printed wiring 40, but when the high-speed printed wiring 40 is selected, the drive pulse is applied to the two common electrodes 32 at the same time. The time T ₀ ′ required for the line emission becomes half of the time T ₀ of the power saving wiring 37, and the printing speed doubles.

By doing so, this edge-emitting type E
In the L printer 34, printing with reduced power consumption by the power-saving wiring 37 and high-speed printing by the high-speed printing wiring 40 can be switchably selected, so that printing work corresponding to various situations can be performed as desired. You can

Here, in the edge emitting EL element 19, the emission intensity gradually increases when the drive pulse is repeatedly applied characteristically, and afterglow remains that gradually decreases when the application of the drive pulse is stopped. When the next light emission operation is started while the afterglow of the previous light emission operation remains, the light emission intensity easily increases. That is, the edge emitting EL element 19
Characteristically, the emission intensity is improved as the number of drive pulses is increased. As illustrated in FIG. 4, even when the high-speed printed wiring 40 is selected as described above, the number of drive pulses does not change, so the print density does not decrease, and it is easy to increase the print speed. .

In this embodiment, as in the second aspect of the present invention, one of the power-saving wiring 37 and the high-speed printed wiring 40 is connected to the edge emitting EL head 30 by the switching operation of the circuit switching means. Although switching between power saving and speedup of the printing operation has been illustrated, the present invention is not limited to the above format. For example, as described in claim 1, by forming the edge emitting EL head 30 having the above-described structure, it is possible to reduce the power consumption and the size and weight of the model, and increase the printing speed and the printing speed. It can be used as a common part with a model that achieves higher quality, and can be applied to the production of edge-emitting EL printers with various characteristics. Further, as in the invention according to claim 3, an edge emitting type E having a structure in which the high speed printed wiring 40 is fixedly connected to the edge emitting type EL head 30 as described above.
By manufacturing the L printer, it is possible to easily produce an edge emitting EL printer having a high printing speed.

[0032]

According to the first aspect of the present invention, m × n edge emitting EL elements are arranged in an array on the head substrate, and m common electrodes are sequentially provided to these edge emitting EL elements. Connect repeatedly and connect n × x block electrodes to edge emitting type E
By connecting every m / x L elements, a common driver is individually connected to each common electrode of this edge-emitting EL head, and n × x block electrodes are provided every n / m. By connecting the block driver, it is possible to implement an edge emitting EL printer that realizes power saving, and further, m / x common drivers are sequentially and repeatedly connected to the common electrode of the edge emitting EL head. At the same time, by individually connecting the block driver to each block electrode, it is possible to implement an edge emitting EL printer that realizes high-speed printing.

According to a second aspect of the present invention, m common drivers are individually connected to m common electrodes of the edge-emitting EL head, and n / x block electrodes are n / m. Power-saving wiring to which the block driver is connected, and m / x common drivers are sequentially and repeatedly connected to m common electrodes of the edge emitting EL head, and n × x block electrodes are n × x blocks. By providing the circuit switching means for selectively switching between the high-speed printed wiring to which the drivers are individually connected, it is possible to select the power saving and the high speed of the printing operation as desired. .

According to a third aspect of the present invention, m / x common drivers are sequentially and repeatedly connected to m common electrodes of the edge-emitting EL head, and n × x block electrodes are n × x block electrodes. By individually connecting the block drivers of (1), it is possible to realize an edge-emitting EL printer that realizes high-speed printing with a simple structure.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an edge emitting EL head according to an embodiment of the present invention.

FIG. 2 is a vertical sectional side view showing an edge emitting EL printer.

FIG. 3 is a time chart.

FIG. 4 is a characteristic diagram of an edge emitting EL device.

FIG. 5 is a block diagram showing a conventional example filed by the applicant in the past.

FIG. 6 is a circuit diagram of a main part.

FIG. 7 is a time chart.

FIG. 8 is a front view of a print image.

[Explanation of symbols]

19 Edge emitting EL device 30 Edge emitting EL head 31 head substrate 32 common electrode 33 block electrodes 34 Edge emitting EL printer 35,38 common driver 36, 39 block driver 37 Power saving wiring 40 high speed printed wiring

Claims (3)

[Claims] 1. A head substrate comprising m × n edge-emitting type Es.
L elements are continuously arranged in an array, and m common electrodes are sequentially and repeatedly connected to these edge emitting EL elements, and n × x block electrodes are provided every m / x of the edge emitting EL elements. An edge emitting EL head characterized in that it is connected to. 2. The m common electrodes are individually connected to the m common electrodes of the edge emitting EL head and n × n common electrodes are connected.
m of the edge emitting EL head and the power-saving wiring in which n block drivers are connected for every m / x of the block electrodes.
A circuit for repeatedly switching m / x common drivers to each common electrode and switching between n × x block electrodes and high-speed printed wiring to which n × x block drivers are individually connected. The edge-emitting EL printer according to claim 1, further comprising switching means. 3. The m / x common drivers are sequentially and repeatedly connected to the m common electrodes of the edge-emitting EL head, and the n × x block drivers are individually provided for every n × x block electrodes. The edge emitting EL printer according to claim 1, which is connected.