JPS62103163A - Optical write printer - Google Patents

Abstract

PURPOSE:To obtain a high ratio of quantity of light, by providing a quantity of light control element controlling a transmission and cut-off of the irradiating light by a movable film which is deflected from an initial position owing to an electrostatic force produced between an electrode in the movable film and an ambient electric field. CONSTITUTION:When a switch 105 is set to an A-side, a potential difference and a capacitive coupling are generated between a movable film 101 and an upper electrode plate 102, thus allowing electrostatic charges to be applied to the movable film 101 to be accumulated therein, which results in the movable film 101 deflected to be in the state 101. At this time, most of an incident light 106 from a light source to a quantity of light control element reaches to a condensing portion 107 without being cut off by the movable film 101, which maximizes the quantity of light used for optical writing. When the switch 105 is set to B-side, an attraction is acted between the movable film 101 and a lower electrode plate 103 by an electrostatic force to return the movable film 101 to the state 201. At this time, the incident light 106 reaches the condensing portion 107 with its minimum quantity of light because being cut-off by the movable film. In this manner, the mechanical movement of the movable film can realize a high max./min. ratio of quantity of light capable of high-speed driving.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer device that performs writing by exposing a photoreceptor or photosensitive paper using light. More specifically, the present invention relates to an optical writing head having a light amount control element that modulates the amount of light emitted from a light source.

[Prior Art] As an exposure method used in an optical writing printer, for example, a method in which light from a point light source such as a laser is focused and exposed by scanning a photoreceptor with a rotating polygon mirror or the like requires a complex high-precision optical system and Requires control system.

On the other hand, in a method that uses a linear light source and exposes the photoreceptor by controlling the amount of light with a light amount control element interposed between the light source and the photoreceptor, a light shutter array that integrates a large number of light amount control elements is placed close to the photoreceptor. This arrangement does not require a complicated optical system or control system, and a general light source such as a fluorescent lamp can be used as a light source, so there is an advantage that the device can be realized with a simple configuration.

As the light amount control element, a liquid crystal shutter has conventionally been used to selectively expose the photoreceptor by transmitting or blocking light according to whether the liquid crystal element is turned on or off. However, with this conventional technology, the response speed of the liquid crystal shutter is slow, the shutter on/off light intensity ratio cannot be large, and the wavelength range of light that can be used is narrow due to the light absorption characteristics and light resistance of the liquid crystal material. It had drawbacks such as being limited.

[Problems to be Solved by the Invention] It is an object of the present invention to solve these problems, to be able to be used in a wide wavelength range, to be applicable to various light sources and photoreceptors, and to be able to
An object of the present invention is to realize an optical writing printer having a light amount control element that has a large light amount ratio when off and is capable of high-speed operation.

[Means for solving the problems] The optical writing printer of the present invention has a part fixed to a substrate,
a movable thin film whose other parts are movable; a mechanism for generating an electric field around the movable thin film; a mechanism for applying an electric charge to the movable thin film; Providing unevenness on one or both of the part of the movable part of the movable thin film Q that contacts the substrate and the part of the substrate that contacts the movable part of the movable thin film, so that the contact area is smaller than when no unevenness is provided. The movable thin film is configured to bend and deform from an initial position due to an electrostatic force between the charges in the movable thin film and a surrounding electric field, thereby controlling transmission and blocking of light irradiated to the movable thin film. Additionally, it is characterized by having a light amount control element.

[Function] According to the above configuration of the present invention, the electrostatic force generated in the movable thin film is changed by controlling one or both of the mechanism for storing charge in the movable thin film and the mechanism for generating an electric field around the movable thin film. However, the amount of deflection deformation of the movable thin film changes accordingly. By changing the amount of deflection deformation of the movable thin film, the amount of transmitted light can be controlled by blocking the light irradiated by the light irradiation mechanism or allowing it to pass through without being blocked.

The present invention performs optical writing on a photoreceptor using a light amount control element as described above.

[Example] The present invention will be explained based on examples.

FIG. 1 is a sectional view showing an embodiment of a printer according to the present invention, in which light from a light source 1 is focused by a condensing lens 2 and irradiated onto a light amount control element 3. The light amount control element 3 controls the amount of reflected light toward the imaging lens 4, and the light focused by the imaging lens 4 exposes one point on the photoreceptor 5. In this way, while performing optical writing, the photoreceptor or
The optical writing system is moved to scan the surface of the photoreceptor.

Figure 2 shows an example in which a line printer is constructed using a light quantity control element array in which a large number of light quantity control elements are integrated in a line shape. The array 13 is irradiated, and the transmitted light is focused and
SELFOC lens array 1 as an imaging lens to form an image
4, form an image on the photoreceptor 5 and perform one optical writing! By moving the photoreceptor 5 in the direction of the arrow, optical writing is performed on the entire plane.

For example, when photosensitive paper is used as the photoreceptor in Figures 1 and 2, processing such as development and fixing may be required. When a latent image is formed, steps such as development, transfer, and fixing using a well-known electrophotographic method are required, but since the present invention relates to a light amount control element, illustrations and explanations of the entire apparatus will be omitted. do. In addition, variations in the configuration of parts other than the light amount control element may be considered, such as guiding light to the light amount control element using a glass fiber or the like without using a condensing lens, but these will not be discussed in detail here. shall be.

Next, a light amount control element according to the present invention will be explained. Third
The figure is a sectional view showing an embodiment of the light amount control element used in the present invention. The upper electrode plate 102 has a transparent conductive film made by Nesa formed as an electrode on the upper surface of a glass substrate, and the lower electrode plate 1
In 03, a transparent conductive film of Nesa is formed as a '@ electrode on the lower surface of a glass substrate. A movable thin gold film 101 is formed on the lower electrode plate 103 with one end adhered via an adhesive layer 104 made of chromium, and a spacer 10 is also formed on the lower electrode plate 103.
There is an upper electrode plate 102 sandwiching 8. A portion of the lower surface of the movable portion of the movable thin film 101 that contacts the lower electrode plate 103 is provided with an uneven surface. A voltage is applied between the upper electrode plate 102 and the lower electrode plate 103 through a power supply, forming a mechanism for generating an electric field around the movable thin film 101. Next, the light amount control operation will be explained. switch 1
05 to side A in the figure, the movable thin film 101 and the lower electrode plate 103 are set to the same potential, and no electrostatic force is generated between them, but the movable thin film 101 and the upper electrode plate 102
Because a potential difference and capacitive coupling occur between the movable thin film 1
An electric charge (negative electric impulse in the case of the power arrangement shown in the figure) is applied and accumulated on 01, and an attractive force is generated between it and the upper electrode plate 102 due to the electrostatic force, and the movable thin film 101 initially becomes 2 as shown by the two-dot chain line in the figure.
What was in the state of 01 was deflected and deformed to 101 in the figure.
reach the state of At this time, most of the light 106 that enters the light amount control element from the light source in the direction C in the figure is transferred to the movable thin film 101.
The light condensing part 10 in the direction shown in the figure without being obstructed by
7, the amount of light used for optical writing becomes maximum.

Next, when the switch 105 is switched to the B side in the figure, an attractive force due to electrostatic force acts between the movable thin film 01 and the lower electrode plate 103, and the movable thin film 101 is in the state 201 shown by the two-dot chain line in the figure. Return to Most of the incident light 106 at this time is blocked by the movable thin film and reflected, scattered, and absorbed, so that the amount of light reaching the condenser 107 is minimized. Also, at this time, due to the unevenness on the lower surface of the movable thin film 101, the movable thin film 10
1 and the lower electrode plate 103 are never in complete contact with each other. Without this unevenness, if the movable thin film 101 is sufficiently thin and flexible, the movable thin film 01 and the lower electrode plate 103 may come into close contact with each other in the state 201 in the figure.

- If the carrier is in close contact with the movable thin film 10, the pressure of the surrounding gas will be
The movable thin film 101 is pressed against the lower electrode plate 103 only on the upper surface of the electrode plate 1.

Assuming that the gas pressure is applied only from the top,
When driven under atmospheric pressure, this pressure is 10-2 kgf/
+n+lff1, and considering the movable thin film 101 simply as a cantilever beam, in addition to the force required to bend and deform it,
It is necessary to apply a large force when peeling off the movable thin film 101 from the adhered state. Now, the thickness of spacer 108 is 0.
．． 05 (n++11), it is calculated that a voltage of approximately 8 KV or more must be applied for this purpose.

In this embodiment, since the movable thin film 101 is provided with unevenness at the part where it contacts the lower electrode plate 103, the degree of adhesion is reduced.
The voltage required to separate the movable thin film 101 and the lower electrode plate 103 from the state in which they are in close contact with each other is significantly reduced, and may be several hundred volts to several tens of volts or less. Examples of the shape of the uneven portion include various shapes as shown in FIGS. 7 to 13.
As shown in FIGS. 2 to 13, irregularities may be formed on both sides of the thin film. Alternatively, irregular irregularities may be created by etching the surface or the like. The unevenness can be produced by pressing a mold against the thin film, removing the recessed parts by etching, or applying a thin film on a sample mold pattern in which the unevenness is reversed, and then removing the female mold. The unevenness may be present on the lower electrode plate side rather than on the movable thin film, or may be present on both sides.

As shown above, in the embodiment of FIG.
05 to change the potential of the movable thin film 101 and bend and deform the movable thin film 101.
It is possible to control the amount of light incident on the light source 7 and used for optical writing. Furthermore, if the switch 105 is not connected to either the A side or the B side in the figure and the movable thin film 101 is placed in an electrically floating state, the electric charge stored before switching to the floating state will be stored as it is, so the movable thin film The force generated on 101 does not change and has a memory effect that keeps it in the same position.

In this embodiment, the upper electrode plate 102 and the lower electrode plate 103 are made by forming a transparent conductive film on a glass substrate so as to transmit light. If so, the entire surface does not necessarily have to be transparent, so if there are windows in these parts, it may be constructed of an opaque material such as a metal electrode plate with an insulating film made of plastic or the like. The movable thin film 101 may be made of any conductive material with low light transmittance, or may be made of a composite structure of a conductor and a non-conductor.When changing the material of the movable thin film 101, the adhesive layer 104 may be The material changes accordingly, and in some cases becomes unnecessary. Furthermore, in this embodiment, the light 106 from the light source enters from the direction C in the figure and reaches the condensing section 107 in the direction C, but this is because the light enters from the direction D and condenses in the direction C. It is also possible to construct a structure that reaches up to 100 mm. Furthermore, in the embodiment shown in FIG. 3, if only the switch 105 is replaced next to the volume a as shown in FIG. 4, the potential of the movable thin film 101 can be set to any potential within the range of the power supply voltage. becomes possible,
The deflection deformation position of the movable thin film 101 can also be set arbitrarily within the range from 101 to 201 in FIG. 3, making it possible to continuously control the amount of light incident on the light condensing section 107.

In addition, in the embodiment shown in FIG. 3, the switch 105 is replaced as shown in FIGS. 5(a) and 5(b), and the movable thin film 10
1 is fixed, and the upper electrode plate 102 and the lower electrode plate 1
The potential of 03 may be changed by a switch. The state of the movable thin film 101 is as shown in FIG.
In the state shown in FIG. 3, the state becomes 101 in FIG. 3, and in the state shown in FIG. 5(b), the state becomes 201 in FIG.

Note that the switches and volumes shown in FIGS. 3 to 5 are not limited to mechanical types, but may be solid-state types using semiconductors or the like.

FIG. 6 is a cross-sectional view of another embodiment of the light amount control element of the present invention, in which the upper electrode plate 102 and the lower electrode plate 103 are not parallel planes, and the interval is small near the base of the movable thin film 101, and the distance is small toward the tip. The points are that the space is widened as the distance increases, that there is no adhesive layer and that the movable vJ thin film 101 is pressed and fixed from the top surface with the spacer 108, and that the unevenness is provided on both sides of the movable thin film 101. The only difference from the embodiment shown in FIG. 3 is that the meanings and operations of the figure numbers are the same. Compared to the embodiment shown in FIG. 3, the electrostatic force when pulling the movable thin film 101 upward is increased, contributing to increased speed and efficiency. Also, when the movable thin film 101 is pulled upward or downward,
Its position is stabilized by contacting the upper or lower electrode plate 102, 103. Therefore, even when a large number of light amount control elements are integrated, it is possible to obtain devices with uniform characteristics with little variation. Furthermore, in this embodiment, since the incident light 106 does not pass through the upper electrode plate 102, the upper electrode plate may be made of an opaque material.

[Effects of the Invention] As shown in the above-mentioned embodiments, the light amount control element used in the present invention has a movable thin film that moves mechanically to block or transmit light, so that a large maximum/minimum light amount ratio can be achieved. The loss caused by passing through the light amount control element is also minimal, and it can be used for light of any wavelength, and there is no need to control the photoreceptor or light source.

In addition, since the movable thin film is configured to flex in response to electrostatic attraction in both the vertical and vertical directions, compared to a method in which the attractive force is applied only in one direction and the movable thin film returns to its original position in the opposite direction using only the elastic force of the movable thin film. This makes it possible to drive at significantly higher speeds. or,
Since the movable thin film is driven by electrostatic force, almost no current flows, making it possible to achieve ultra-low power consumption. In addition, since the movable thin film and the substrate are provided with unevenness at the contact portion, the degree of adhesion at the time of contact is reduced, and the influence of ambient gas pressure and intermolecular force that occur when they are in close contact can be reduced. Even when the movable thin film and the substrate are separated from each other when they are in contact with each other, a large voltage is not required and it can be driven at a low voltage. In addition, by placing the movable thin film in a floating state, it has a memory effect that retains the previous state, so even when a large number of light amount control elements are integrated, dynamic driving by time division is easy, and the number of driving drivers can be reduced. can be reduced. Furthermore, since the light amount control element of the present invention can be manufactured using the same film-forming technology and patterning/etching technology as in semiconductor manufacturing processes, it is easy to manufacture a large number of integrated elements with high precision.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the exposure section of the optical writing printer of the present invention. FIG. 2 is a diagram showing an embodiment in which a large number of light amount control elements are integrated. FIG. 3 is a sectional view showing one embodiment of the light amount control element used in the present invention. FIG. 4 is a diagram showing another embodiment of the switch 105 in FIG. 3. FIGS. 5(a) and 5(b) show the switch 105 in FIG.
FIG. 6 is a cross-sectional view showing another embodiment of the light amount control element used in the present invention, in which (a) and (b) show two states in which the switch is switched. figure. Figures 7 to 13 are acceptable! FIG. 3 is a diagram showing an example of unevenness provided in the contact portion between the JJ thin film and the substrate. 3... Light amount control element 13... Light amount control element array 101... More than movable thin film

Claims (1)

[Claims] A movable thin film having a part fixed to a substrate and the other part movable, a mechanism for generating an electric field around the movable thin film, a mechanism for applying an electric charge to the movable thin film, and irradiating light to the movable thin film. a mechanism, wherein one or both of a portion of the movable portion of the movable thin film that contacts the substrate and a portion of the substrate that contacts the movable portion of the movable thin film are provided with unevenness, the contact area is uneven. The structure is such that the movable thin film is deflected from its initial position due to the electrostatic force between the charges in the movable thin film and the surrounding electric field, and the light irradiated onto the movable thin film is transmitted and deformed. An optical writing printer comprising a light amount control element configured to control interruption.