JPS62199465A - Heat ray radiation head - Google Patents

Abstract

PURPOSE:To make it possible to reduce light emitting irregularity, in a heat ray radiation head for an optical printer, by enlarging the height of the air gap formed between the substrate between electrodes and a radiation resistor by providing a groove to the substrate under a radiation part. CONSTITUTION:When a printing signal is applied to the electrodes 16 of a heat ray head 14, heat rays are emitted from a radiation resistor 18 to form an electrostatic latent image on a photosensitive drum 6 through a rod array lens 13 and a toner image is formed by a developing device 18 to be transferred to a recording paper 11 by a transfer device 19. This heat ray head 14 is formed by forming the electrodes 16 and the radiation resistor 18 opposed through an air gap 17 on a low heat conductivity substrate 15 such as glass in a film form and providing a groove 20 with a depth of about 3mum to the substrate 15 at the position corresponding to the radiation part 19 of the air gap 17 by etching to form the sufficiently large air gap. By this method, the earthing of the radiation resistor to the substrate is prevented and light emitting irregularity is reduced while reliability is enhanced and printing quality can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat ray emitting head that emits infrared rays, near infrared rays, visible rays, etc. and is used as a head for an optical printer.

[Conventional technology]

A heat ray emitting head generates heat and emits light by energizing a radiator, and is used as a head for an optical printer in the same way as an LED array.A conventional example will be described below with reference to the drawings.

Figure 3 is a cross-sectional view. In the figure, 1 is a substrate with low thermal conductivity such as glass, 2 is a metal electrode placed oppositely on this substrate 1 with an air gap 3, and 4 is a gap between the metal electrodes 2. Reed with a radiation resistor placed across the air gap 3 above.
The location corresponding to is the radiation part 5, which is floating above the substrate 1.

An example of a method for manufacturing a heat ray radiation head configured in this manner is as follows.

That is, an electrode layer and a radiation resistor layer are sequentially formed on the substrate 1.

Next, the radiation resistor 4 is patterned by photolithography.

Next, parts other than the radiation part 5 are covered with resist by photolithography, and the electrode layer under the radiation resistor 4 of the radiation part 5 is removed by etching.

Finally, using the pattern of the radiation resistor 4 as a mask, the electrode was chisel-turned by etching.

[Problem 3 to be solved by the invention According to the heat ray emitting head described above: The height of the gap is determined by the thickness of the metal electrode. Therefore, in reality, electrodes are formed with a thickness of about 1.5 to 5 μm, but it is inconvenient to increase the thickness of the electrodes due to the problem of side etching during etching, and as a result, the height of the gap increases. It is difficult to obtain a large value.

Therefore, since the height of the gap is not sufficient, the radiation resistor may come into contact with the substrate, resulting in uneven brightness between printed dots and deterioration of printing quality.

[Means for solving problems]

The present invention is characterized in that a recess is provided in the substrate below the gap corresponding to the radiation portion of the radiation resistor to provide a heat ray radiation head with a sufficient distance between the radiation resistor and the substrate.

[Effect]

An electrode layer and a radiation resistor layer are sequentially formed on the substrate, the radiation resistor is patterned by etching, the area other than the radiation part is covered with resist, and the electrode layer under the radiation is removed by etching, and then the radiation resistor layer is deposited on the substrate. A heat ray emitting head is obtained by etching the patterned radiation resistor to form a groove, and then etching the electrode layer using the patterned radiation resistor as a mask to form an electrode. By applying electricity to the radiation resistor, the radiation resistor is heated by sidual heat, and the radiating section generates heat ray radiation, and this heat ray radiation is radiated to the photosensitive drum to expose the photoreceptor of the photosensitive drum to perform printing. can.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is an overall side view of the electrophotographic printer. In the figure, 6 is a photosensitive drum, which rotates in the direction of the arrow. 7 is a charging device, 8 is a developing device, 9 is a transfer device, and 10 is a cleaner, which are similar to those in a generally used electrophotographic process and are arranged in the above order.

1g is a recording paper, a toner image is transferred by a transfer device 9, and the toner image is passed through a fixing plate 12. 13 is a rod array lens.

14 is a heat ray radiation head. This heat ray radiation head will be explained with reference to FIG.

FIG. 1 is a cross-sectional view. In the figure, 15 is a substrate with low thermal conductivity such as glass, 16 is an electrode placed opposite to each other with a gap 17 in between, and 18 is a radiator placed between these electrodes 16. It is a resistor, and the portion corresponding to the gap 17 is a radiation portion 19. Reference numeral 20 denotes a groove provided in the substrate 15 at a location corresponding to the radiation portion 19.

An example of a method for manufacturing a heat ray emitting head having the above configuration will be shown below.

For the substrate 15, alkali-free glass was used.

On this substrate 15, Or 120OA, Au 2.5μm
.

Films were formed by sputtering to form an electrode layer and a radiation resistor layer.

Next, the radiation resistor 18 is formed by patterning the TaC by photolithography.

Next, e) the electrode layer under the IJ radiation part 19 is removed by etching Cr and Au by covering the area other than the radiation part 19 with resist using an IJ saw.

Subsequently, using the removed electrode layer as a mask, the substrate 15 below the radiation portion 19 is etched to form a groove 20 of 3 μm.

Subsequently, the resist is removed, and Cr and Au are etched using the pattern of the radiation resistor 18 as a mask to form the electrode 16 to form a heat ray radiation head.

As described above, the present method is characterized in that after etching the electrode layer under the radiation, the substrate can be etched using the electrode layer as a mask, and no special masking step is required. Further, the materials, film forming methods, etching methods, etc. mentioned above are not limited to those mentioned above, and the thickness of each film and the depth of the grooves may be determined according to the required performance.

〔Effect of the invention〕

According to the present invention described in detail above, by forming a groove in the substrate below the radiation of the radiation resistor to form a sufficiently large air gap, the radiation resistor is no longer grounded to the substrate, and uneven light emission is prevented. It is possible to create a highly reliable heat ray emitting head with less heat rays.

In addition, by setting the groove depth to a predetermined depth, the height of the shear gap can be determined regardless of the electrode thickness, so there is no need to increase the electrode thickness, and the electrode width can be reduced by side etching during etching. This has the effect of eliminating the problem of miniaturization.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a side view of an electrophotographic printer using the heat ray head of the present invention, and FIG. 3 is a sectional view of a conventional heat ray head. be. 15... Substrate 16... Electrode 1T... Air gap 18... Radiation resistor 19... Radiation part 20.
... Mizo patent applicant Takashi Kanakura, patent attorney for Oki Electric Industry Co., Ltd. Side view shaft 2 of a printer using two types of heat ray emitting heads
Conventional cross-section map for public relations 3 b

Claims (1)

[Claims] 1. A radiation resistor is passed between electrodes provided on a substrate, and an air gap is formed between the substrate and the radiation resistor between the electrodes,
A heat ray radiation head in which a radiation resistor at that location is used as a radiation part, characterized in that a groove is provided in a substrate below the radiation to increase the height of the air gap.