JPH03219976A - Edge emission type el printer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an edge-emitting EL printer that forms images by electrophotography.

2. Description of the Related Art In recent years, line printers are one of the printers developed using electrophotography.

This line printer is a device in which devices such as a charger, line head, developer, transfer device, etc. are arranged close to the circumferential surface of a photosensitive drum. A latent image is formed by exposure using selective light emission from a light emitting element connected to a line head, and this latent image is developed with toner supplied from a developing device and transferred onto printing paper by a transfer device. be.

The light emitting element of the line head as mentioned above is LED (
However, since it is difficult to correct the difference in light emitting intensity that exists between elements, productivity is low.Currently, edge-emitting type EL (EL) is used as the light emitting element for line heads.
It is considered to use a ctroluminescence) element. Therefore, a line head using such an edge-emitting type EL element will be explained based on FIGS. 7 and 8. Edge-emitting type E of this line head L
As illustrated in FIG. 8, the L element 2 includes a thin active layer 3 made of zinc sulfide containing an active element, surrounded by dielectric layers 4 and 5 from above and below, and a layer on top of these dielectric layers 4 and 5. Flat plate electrodes 6 and 7 are formed on the bottom surface, and extremely flat light is emitted from the end surface of the active layer 3'', and it is possible to obtain a luminous intensity approximately 100 times higher than that of a conventional EL in which light is emitted from the top surface. It is possible.

Then, as illustrated in FIG. 7, the line head l is formed by continuously forming the edge emitting type EL elements 2 having the above structure using thin film technology and attaching a rod lens array (not shown), etc. It is formed.

Therefore, by connecting a drive circuit to the line head l having the structure described above and arranging it along with a charger, developing device, transfer device, etc. on the circumferential surface of the photosensitive drum, which is a photosensitive member, an electrophotographic line printer can be produced. An edge-emitting EL printer (
(not shown) can be manufactured.

Problems to be Solved by the Invention Various types of driving methods for the line head 1 as described above are possible, but as illustrated in FIG. common electrode 8
．． It was proposed to drive the line head 1 in a matrix by wiring ~8m and n block electrodes 9 and ~9n in a matrix and applying synchronously controlled high-voltage and low-voltage drive pulses to these electrodes 8 and 9. .

The line head l wired in a matrix in this manner is driven by a high-output, low-power drive circuit (both not shown) in which a drive power source is connected to each of the common electrodes 8□ to 8m and the block electrodes 9 to 9n. ).

However, when implementing such a drive circuit, the common electrode 8. Wiring and common electrode leading to the drive circuit for ~8m 8. The influence of external noise on the distance of ~8 m becomes a problem. In addition, a stabilized power supply (not shown) is generally used as a drive power source for the drive circuit described above, but this occupies a large volume and is heavy, which hinders miniaturization and weight reduction of devices. Become.

Means for Solving the Problem A line head consisting of a large number of edge-emitting EL elements is wired in a matrix with common electrodes and block electrodes, and a common drive circuit connected to the common electrode is connected to a DC-DC converter. The DC converter, common drive circuit, and line head are integrally formed.

By wiring a line head consisting of many edge-emitting type E'L elements in a matrix with common electrodes and block electrodes, connecting a common drive circuit to the common electrode, and connecting a DC-DC converter to this common drive circuit. Since the DC-DC converter occupies a small volume and is lightweight, it can contribute to making the device smaller and lighter.By integrally forming the DC-DC converter, common drive circuit, and line head, the DC-DC converter and It is possible to simplify the large-capacity and complicated wiring that connects the common drive circuit and the line head.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 6. First, as illustrated in FIG. 1, this edge-emitting EL printer 10 includes a charger 12, a line head 13, a developer 14, a transfer device 15, a toner cleaner 16, and a static eliminator on the circumferential surface of a photosensitive drum 11. The structure is such that devices such as lamps 17 are sequentially arranged facing each other, and a conveyance path for printing paper (not shown) is formed between the photosensitive drum 11 and the transfer device 14.

Here, as illustrated in FIG. 3, the line head 13 includes m common electrodes 181 to 18m and n block electrodes 19. mXn matrix-wired with ~19n
edge-emitting type EL elements 2, a self-reflection array 20 located on the front surface thereof, and the block electrode 19.
The block drive circuit 21 connected to the block drive circuit 21 is formed in parallel on the - number of substrates 22. on the other hand,
A circuit housing 25 is mounted on the main body frame 23, in which the toner cleaner 16 and the like are integrally formed, with bolts 24 and the like.
A mounting plate 26 to which the board 22 of the line head 13 is fixed is movably mounted to the rear surface of the circuit housing 25 with bolts 24 or the like. Here, wiring holes 27 and 28 are formed in the mounting plate 26 and the circuit housing 25 to communicate with each other.
and each electrode 18, 19 of the line head 13 are connected by a connection cable 30. Further, the circuit board 29, which is attached to the bottom surface of the circuit housing 25 with bolts 24 via a spacer 31, connects to a common drive circuit 32 connected to the common electrode 18, as illustrated in FIG. A DC converter 33 is formed in parallel.

A common drive circuit 32 on the circuit board 29
and the DC=DC converter 33 are connected to the main body power supply and a control circuit (both not shown) by low voltage cables 35 and 36, respectively, through the wiring hole 34 on the front surface of the circuit housing 25. For example, the DC-DC converter 33 generates high voltage power of about 250V or low voltage power of about 30.15°5V from input low voltage power of 24V,
The common drive circuit 32 to which these powers are supplied
and the block drive circuit 15 output high-voltage and low-voltage drive pulses to the line head 13, respectively.

Therefore, in this edge-emitting EL printer 10, the D
C-DC converter 33 and the common drive circuit 32
and the line head 13 are integrally formed.

The mounting plate 26 is made of iron, aluminum, or the like with good heat dissipation, and the cables 30, 35, 36, etc. are made of shielded wires or coaxial cables that have high resistance to external noise.

In this configuration, in this edge-emitting EL printer 10, the common drive circuit 32 and the block drive circuit 15, to which high-voltage and low-voltage power is supplied from the DC-DC converter 33, are synchronously controlled. Electrode 19. ~19n and common electrode 18. Low and high voltage drive pulses are output to the line head 13 from ~18 m, respectively, and the potential of this composite pulse drives each edge-emitting type EL.
Element 2 is selectively activated.

In this edge-emitting type EL printer 10, the time T for forming one main scanning line is as shown in the time chart illustrated in FIG. A plurality of drive pulses are applied to the line head 13 during the process, and, for example, the device light emission of each edge-emitting type EL device 2 is repeated once for a region forming one pixel.

By doing so, the flat pixel components formed by one light emission of the edge-emitting type EL element 2 are arranged consecutively in the sub-scanning direction within one pixel area, as shown in FIG. Thus, even if the beam shape of the edge-emitting type EL element 2 is flat, substantially square pixels can be obtained, and the occurrence of gaps in pixels is also prevented, thereby improving printing quality.

Here, the common drive circuit 32 outputs high voltage pulses and therefore consumes a large amount of power, but in this edge-emitting type E'L printer 10, the line head 13, the common drive circuit 32, and the DC-DC converter 33 are integrated. This simplifies the large-capacity and complicated wiring that connects these members 13, 32, and 33, prevents the intrusion of external noise, simplifies the structure, improves productivity, and improves drive speed. The S/N ratio has also improved. Furthermore, in the edge-emitting EL printer lO of this embodiment, the DC-DC converter 33
The main body frame 23 is formed by integrally forming the common drive circuit 32 and line head 13 with the circuit housing 25 and the like.
Since the line head 13 is mounted on the top, it is easy to assemble the line head 13 to the main body of the apparatus, and its positional accuracy with respect to the circumferential surface of the photosensitive drum 11 is high.

In addition, this edge-emitting EL printer 10 uses a C-DC converter 33 as the drive power source for the line head 13, which occupies a smaller volume and is lighter than a stabilized power source, etc., which contributes to making the device smaller and lighter. can do.

Effects of the Invention As described above, the present invention connects a line head consisting of a large number of edge-emitting EL elements in a matrix with common electrodes and block electrodes, connects a common drive circuit to the common electrode, and connects a DC to this common drive circuit. -By connecting a DC converter, the DC-DC converter occupies a small volume and is lightweight, so it can contribute to making the device smaller and lighter.The DC-DC converter, common drive circuit, and line head can be integrated. Due to this, DC
- It is possible to simplify the large-capacity and complicated wiring that connects the DC converter, common drive circuit, and line head, improving equipment productivity and preventing external noise from entering the line head drive pulse. It has the effect of being able to prevent such problems.

[Brief explanation of drawings]

Fig. 1 is a vertical side view showing an embodiment of the present invention, Figs. 2 and 3 are block diagrams, Fig. 4 is a perspective view of main parts, Fig. 5 is a time chart, and Fig. 6 is a printed image. Plan view shown, No. 7
The figure is a perspective view showing the line head, and Figure 8 is the edge-emitting type E.
FIG. 9 is a perspective view showing the L element and a circuit diagram showing the wiring structure of the line head proposed by the applicant.

Claims (1)

[Claims] A line head consisting of a large number of edge-emitting EL elements is wired in a matrix with common electrodes and block electrodes, a common drive circuit is connected to the common electrode, a DC-DC converter is connected to this common drive circuit, and this DC
- An edge-emitting EL printer characterized in that a DC converter, the common drive circuit, and the line head are integrally formed.