JPH079694A - Imaging device - Google Patents

Abstract

PURPOSE:To generate an accurate electric signal corresponding to external image information in a solid image pickup element array by a method wherein a photosensitive material surface is accurately irradiated with light emitted from a light emitting diode via a lens, and a latent image of a high image quality is formed on the photosensitive material, or the external image information is accurately imaged on the solid image pickup element array via the lens. CONSTITUTION:An imaging device is provided wherein it is composed of a lens plate 2 supporting a plurality of lenses 5 and a base plate 1 on which an array 4 of a plurality of image elements is placed, and the lens plate 2 and the base plate 1 are jointly provided to be fixed so that each lens 5 can correspond to each image element array 4 by one to one via a spacer. A thermal expansion coefficient of the lens plate 2 is made actually as same as that of the base plate 1. Besides, a regulation member 7 which regulates a distance from the lens 5 to the photosensitive material 6 is attached to any one of the lens plate 2, the base plate 1, and the spacer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus used in an image forming apparatus such as an optical printer head or an image reading apparatus such as an image sensor.

[0002]

2. Description of the Related Art A conventional image forming apparatus, for example, an image forming apparatus used in an image forming apparatus such as an optical printer head is usually made of a resin such as polycarbonate in which a plurality of lenses are linearly arranged and supported on a support at predetermined intervals. Each lens and each light emitting diode element array have a one-to-one correspondence between the lens plate consisting of and the base plate made of aluminum oxide sintered body or glass on which many light emitting diode element arrays are arranged linearly. The light emitting diodes of each light emitting diode element array are made to selectively emit light in response to an external electric signal, and the light emitted by each light emitting diode element is lensed. An image is formed on the surface of the external photoconductor via the, and a latent image is formed on the photoconductor to function as an image forming apparatus.

The light emitting diode element array linearly arranged and mounted on the base plate is generally composed of 64 light emitting diode elements linearly arranged therein, and is a B4 size image forming apparatus. In the case of using the above, the 32 light emitting diode element arrays are mounted on the base plate so that each of the 32 light emitting diode element arrays corresponds to each lens one to one.

Further, when each lens supported by the lens plate and each light emitting diode element array mounted on the base plate are displaced from each other, bleeding, white lines, and black are formed on the image formed on the photosensitive member. Each lens and each light emitting diode element array are aligned with extremely high precision because it is impossible to form a sharp and accurate latent image by generating streaks or the like.

[0005]

However, in this conventional image device, a lens plate made of a resin such as polycarbonate that supports the lens and an aluminum oxide sintered body or glass on which the light emitting diode element array is mounted are used. Each of the base plates has a thermal expansion coefficient of 1.
9 × 10 ^-5 / ℃, 4.0 ~ 7.5 × 10 ^-6 / ℃, which is a big difference, so when this image device is installed in an image forming apparatus and used, heat is applied to both the lens plate and the base plate. Then, the lens plate thermally expands much more than the base plate, and as a result, a position shift occurs between the lens supported by the lens plate and the light emitting diode element array mounted on the base plate, resulting in a clear and accurate photoconductor surface. It has a drawback that it is not possible to form a large latent image.

In the above-mentioned conventional example, an image device used in an image forming device such as an optical printer head has been described as an example, but a solid-state image sensor array (CCD element array) is used.
Even in an image device used in an image reading device such as an image sensor using, the image formation of the external image information on the solid-state image sensor array becomes uneven due to the positional deviation between the lens and the solid-state image sensor array, It has a drawback that it is impossible to generate an accurate electric signal corresponding to image information in the solid-state imaging device array.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and an object thereof is to accurately irradiate the photoconductor surface with light emitted by a light emitting diode element through a lens so that a latent image of high image quality is formed on the photoconductor. Or an image device capable of accurately forming an external image information on a solid-state image sensor array through a lens and generating an accurate electric signal corresponding to the external image information on the solid-state image sensor array. To provide.

[0008]

The present invention comprises a lens plate having a plurality of lenses linearly arranged and supported at predetermined intervals, and a base plate having a large number of image element arrays linearly arranged and mounted thereon. The lens plate and the base plate are fixed side by side via a spacer so that each lens and each image element array are in a one-to-one correspondence, and the light emitted from the image element array is applied to the photoconductor through the lens, or external image information is transmitted. An image device for forming an image on an image element array through a lens, wherein a lens plate supporting the lens and a base plate on which the image element array is mounted have substantially the same thermal expansion coefficient, and the lens plate and the base plate An adjusting member for adjusting the distance between the lens and the photoconductor or external image information is attached to at least one of the spacers. And are characterized by.

The present invention is also characterized in that the adjusting member is provided with a vibration absorbing property.

[0010]

According to the image device of the present invention, since the lens plate supporting the lens and the base plate on which the image element array is mounted have substantially the same thermal expansion coefficient, heat is applied to both the lens plate and the base plate. Even if applied, the lens plate and the base plate are thermally expanded by substantially the same amount, and there is no positional deviation between each lens and each image element array. As a result, this image device can be used for an optical printer head or the like. When used in an image forming device, the light emitted from each light emitting diode element is well irradiated to the entire surface of the photoconductor, which makes it possible to form a clear and accurate latent image on the photoconductor. When used in an image reading device such as a sensor, external image information can be accurately formed on the entire surface of the solid-state image sensor array via a lens, and It is possible to generate an accurate electrical signal corresponding to the external image information element array.

Further, according to the image device of the present invention, since at least one of the lens plate, the base plate and the spacer is provided with the adjusting member for adjusting the distance between the lens and the photoconductor or the external image information, the heat of the lens plate is reduced. The expansion (expansion) of the interval (pitch) between the adjacent lenses due to the expansion makes it impossible to irradiate the entire surface of the photoconductor with light or to form the external image information on the entire surface of the image sensor array. Can be corrected by adjusting the distance between the photoconductor and the external image information, and as a result, the entire surface of the photoconductor is irradiated with light or the external image information is well formed on the entire surface of the solid-state image sensor array. It becomes possible.

Further, according to the image device of the present invention, since the adjusting member is provided with the vibration absorbing property, even if an impact force is applied to the adjusting member from the photoconductor or external image information, the impact force is applied to the adjusting member. It is not absorbed by itself and applied to the lens plate, base plate, etc. As a result, there is no risk of damage to the lenses arrayed and supported on the lens plate or the image element array mounted on the base plate. It is possible to irradiate light on the entire surface of the photoconductor or to form external image information on the entire surface of the solid-state image pickup element array over a period.

[0013]

The present invention will now be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment in which the image forming apparatus of the present invention is adopted in an optical printer head as an image forming apparatus. 1 is a base plate, 2 is a lens plate, 3 is a spacer, and 4 is a light emitting diode element array. , 5 are lenses.

The base plate 1 is made of an electrically insulating material such as glass epoxy resin, and a plurality of light emitting diode element arrays 4 are linearly arranged and mounted on the upper surface thereof.

The base plate 1 acts as a supporting member for supporting the light emitting diode element array 4, and is manufactured by pouring a sol-like epoxy resin into glass fiber and then thermosetting the epoxy resin. .

The light emitting diode element array 4 arranged and mounted on the base plate 1 is composed of a plurality of light emitting diode elements 4a, and the light emitting diode elements 4a individually and selectively emit light in response to an external electric signal. Then, the surface of the photoconductor 6 is irradiated with the emitted light to form a latent image for forming an image on the photoconductor 6.

The light emitting diode element 4a is a GaAsP type, Ga
P-based light-emitting diodes are used.For example, in the case of GaAsP-based light-emitting diodes, the GaAs substrate is first heated to a high temperature in a furnace and AsH ₃ (arsine), PH ₃ (phosphine), Ga (gallium) are used. ) Is contacted with a gas to grow a single crystal of n-type semiconductor GaAsP (gallium-arsenic-phosphorus) on the substrate surface, and then Si ₃ is grown on the GaAsP single crystal surface.
A windowed film of N ₄ (silicon nitride) is deposited, and Zn (zinc) gas is exposed to the window to form an n-type semiconductor GaAsP.
Zn is diffused into a part of the single crystal to form a p-type semiconductor, and pn
It is formed by providing a bond.

In the case of a B4 size optical printer head, the number of the light emitting diode elements 4a is 2048 (8 per 1 mm).
Are arranged in a straight line, specifically, a light emitting diode element array in which 64 light emitting diode elements 4a are one unit.
By arranging 32 4 linearly, 2048 light emitting diode elements 4a are arranged on the base plate 1.

Further, the base plate 1 on which the light emitting diode element array 4 is mounted is provided with a lens plate 2 on the upper part thereof with a certain distance, and a plurality of holes 2a are linearly formed in the lens plate 2. The lenses 5 are arrayed and fixed so as to close the holes 2a via an adhesive material such as resin.

The lens plate 2 includes a plurality of lenses 5
Acts as a support member that supports the
Reference numeral 2a has a function of transmitting light emitted from each light emitting diode element 4a of the light emitting diode element array 4 to the photoconductor 6 side.

The lens plate 2 is made of a material having substantially the same thermal expansion coefficient as the base plate 1 on which the light emitting diode element array 4 such as glass epoxy resin is mounted. Is substantially the same as the thermal expansion coefficient of the base plate 1, so when used as a light source for an electrophotographic printer, even if heat is applied to both the lens plate 2 and the base plate 1, the lens plate 2 and the base plate 1 There is no positional deviation between each lens 5 and each light emitting diode element array 4 due to thermal expansion by approximately the same amount, and as a result, the light emitted by each light emitting diode element 4a is exposed through the lens 5. It is possible to form a high-quality latent image on the photoconductor 6 by accurately and clearly forming an image on the surface of the body 6.

Further, each lens 5 supported by the lens plate 2 is a photosensitive member for the light emitted by each light emitting diode element 4a.
A lens formed of a transparent resin such as an acrylic resin or a polycarbonate resin, or a transparent inorganic material such as glass, which has an effect of irradiating six surfaces, is preferably used.

Incidentally, each lens 5 is linearly adhered to the lens plate 2 at predetermined intervals by adhering a part of the outer surface to the lens plate 2 via an adhesive such as resin.

The base plate 1 on which the light emitting diode element array 4 is mounted and the lens plate 2 on which the lens 5 is supported are fixed to the spacers 3, so that each light emitting diode element array 4 and each lens 5 are fixed. And are placed side by side in a one-to-one correspondence with a predetermined distance.

The spacer 3 has a first reference surface on the top thereof.
3a and the second reference surface 3b at the bottom,
Each light emitting diode element array 4 and each lens 5 are fixed by abutting and fixing the outer peripheral portion of the lower surface of the lens plate 2 to the first reference surface 3a of the 1 to 1 with a certain distance in between
It corresponds to.

The spacer 3 is, for example, a base plate.
It is made of the same material as 1 and the lens plate 2, specifically glass epoxy resin.

Further, an adjusting member 7 for adjusting the distance between the lens 5 and the photoconductor 6 is attached to at least one of the base plate 1, the lens plate 2 and the spacer 3.
The adjusting member 7 allows the distance between the lens 5 and the photoconductor 6 to be arbitrarily adjusted.

When the adjusting member 7 is used as a light source of an electrophotographic printer, heat is applied to the lens plate 2, and due to the thermal expansion of the adjusting member 7, the interval (pitch) between the adjacent lenses 5 is expanded. It is impossible to irradiate the light emitted from the light-emitting diode element 4a on the entire surface of the photoconductor 6 without any gap. Adjust the distance between the lens 5 and the photoconductor 6 to widen the light irradiation area by the lens 5. The lens 5 has the effect of compensating for the entire surface of the photoreceptor 6
Light emitted from the light emitting diode element 4a is emitted via the light emitting element, and a predetermined latent image can be accurately and clearly formed on the photoconductor 6.

If the coefficient of thermal expansion of the adjusting member 7 is set to 1 / (2 · Tan θ) with respect to the coefficient of thermal expansion of the lens plate 2, the photosensitive member 6 due to the thermal expansion of the lens plate 2 is applied. The inconvenience of light irradiation is automatically corrected by the adjusting member 7, and the light emitted from the light emitting diode element 4a can always be applied to the entire surface of the photoconductor 6 via the lens 5. Therefore, it is preferable that the adjusting member 7 has a coefficient of thermal expansion of 1 / (2 · Tan θ) with respect to the coefficient of thermal expansion of the lens plate 2.

Further, the adjusting member 7 has a roller 7a arranged at the upper end thereof formed of elastic rubber, or the adjusting member 7 itself is made of a liquid crystal polymer resin excellent in vibration absorption characteristics (for example, called Vectra manufactured by Polyplastics Co., Ltd.). Liquid crystal polymer), or if the adjusting member 7 is provided with a plurality of band-shaped through holes to impart vibration absorption, the adjusting member is attached to the photoconductor 6.
When a latent image for forming an image is formed on the photoconductor 6 by adjusting the distance between the lens 5 and the photoconductor 6 by bringing the photoconductor 6 into contact with the photoconductor 7, an impact force is applied from the photoconductor 6 to the adjusting member 7. The impact force is absorbed by the adjusting member 7 itself and the lens plate
No impact force is applied to the base plate 2 and the base plate 1, and as a result, the lenses 5 arrayed and supported by the lens plate 2 and the image element array 4 mounted on the base plate 1 are not damaged. Instead, it becomes possible to accurately irradiate the entire surface of the photoconductor 6 with the light emitted from the light emitting diode element 4a through the lens 5 for a long period of time.

Thus, according to the image device of the present invention, a predetermined electric power is applied to each light emitting diode element 4a of the light emitting diode element array 4 linearly mounted on the base plate 1 so that each light emitting diode element 4a is driven. In addition to individually and selectively emitting light, the light emitted from each light emitting diode element 4a is imaged on the surface of the external photoconductor 6 through the lens 5,
By forming a predetermined latent image on the photoconductor 6, it functions as an image forming apparatus.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned embodiments, the base plate 1 and the lens plate 2 can be modified. Both of them are made of lath epoxy resin, but any material can be used for the base plate 1 and the lens plate 2 as long as they have substantially the same thermal expansion coefficient.
Lens plate 2 when is made of glass epoxy resin
Can be formed by glass fiber reinforced nylon, glass fiber reinforced nylon, glass fiber reinforced polyphenylene sulfide resin, glass fiber reinforced acrylonitrile = butadiene = styrene copolymer, or a mixture of at least two of these materials. Good.

Further, between the base plate 1 and the lens plate 2, and adjacent to the light emitting diode element array.
If a light-shielding plate 8 is arranged between the light-emitting diode element arrays 4, even if the light emitted from the light-emitting diode elements 4a of each light-emitting diode element array 4 leaks to the adjacent light-emitting diode element array 4 side, the leakage is completely prevented by the light-shielding plate 8. As a result, the light emitted from the light emitting diode element 4a of each light emitting diode element array 4 is irradiated and imaged on the photoconductor 6 only through the lens 5 corresponding to it one by one, and is not imaged on the photoconductor 6. Bleeding and the like due to the irradiation of such light is eliminated, and an extremely clear latent image can be formed. Therefore, the base plate
It is preferable to dispose a light shielding plate 8 between 1 and the lens plate 2 and between the adjacent light emitting diode element arrays 4.

Further, in the above-described embodiment, the case of using it in an image forming apparatus such as an optical printer head has been described as an example. However, the light emitting diode element array is changed to a solid-state image pickup element array to be used as an image reading apparatus such as an image sensor. Can also be used.

[0035]

According to the image device of the present invention, since the thermal expansion coefficient of the lens plate supporting the lens and the base plate on which the image element array is mounted are substantially the same, both the lens plate and the base plate. Even if heat is applied to the lens plate and the base plate, the lens plate and the base plate are thermally expanded by substantially the same amount, and no positional deviation occurs between each lens and each image element array. When used in an image forming device such as a head,
The light emitted from each light-emitting diode element is satisfactorily applied to the entire surface of the photoconductor, and it becomes possible to form a clear and accurate latent image on the photoconductor. Also, this image device can be used as an image reading device such as an image sensor. When used, the external image information can be accurately formed on the entire surface of the solid-state imaging device array through the lens, and the solid-state imaging device array can generate an accurate electric signal corresponding to the external image information. Become.

Further, according to the image device of the present invention, since at least one of the lens plate, the base plate and the spacer is provided with an adjusting member for adjusting the distance between the lens and the photosensitive member or the external image information, the heat of the lens plate is reduced. The expansion (expansion) of the interval (pitch) between the adjacent lenses due to the expansion makes it impossible to irradiate the entire surface of the photoconductor with light or to form the external image information on the entire surface of the image sensor array. Can be corrected by adjusting the distance between the photoconductor and the external image information, and as a result, the entire surface of the photoconductor is irradiated with light or the external image information is well formed on the entire surface of the solid-state image sensor array. It becomes possible.

Further, according to the image device of the present invention, since the adjusting member is provided with the vibration absorbing property, even if an impact force is applied to the adjusting member from the photoconductor or external image information, the impact force is applied to the adjusting member. It is not absorbed by itself and applied to the lens plate, base plate, etc. As a result, there is no risk of damage to the lenses arrayed and supported on the lens plate or the image element array mounted on the base plate. It is possible to irradiate light on the entire surface of the photoconductor or to form external image information on the entire surface of the solid-state image pickup element array over a period.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which an image forming apparatus of the present invention is applied to an optical printer head as an image forming apparatus.

FIG. 2 is a sectional view taken along line XX of FIG.

[Explanation of symbols]

 1 ... Base plate 2 ... Lens plate 3 ... Spacer 4 ... Light emitting diode element array 4a ... Light emitting diode element 5 ... Lens 7 ... Adjustment member

Claims (2)

[Claims] 1. A lens plate having a plurality of lenses linearly arranged and supported at a predetermined interval, and a base plate on which a large number of image element arrays are linearly arranged and mounted. The lens plate and the base plate are provided. Each lens and each image element array are fixed side by side via a spacer so as to correspond to each other, and the light emitted from the image element array is applied to the photoconductor through the lens, or external image information is passed through the lens to the image element array. An image device for forming an image on the lens plate, the lens plate supporting the lens and the base plate on which the image element array is mounted have substantially the same thermal expansion coefficient, and at least one of the lens plate, the base plate and the spacer is provided. An image device including an adjusting member for adjusting a distance between a lens and a photoconductor or external image information. 2. The image device according to claim 1, wherein the adjusting member has a vibration absorbing property.