JPH1051587A - Image read-write head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image read-write head which has an image read function as an image sensor and an image recording function as a thermal print head, in which a characteristic change in a read element resulting from overhead of a heat generating element is reduced or eliminated. SOLUTION: The image read-write head 1 is provided with a plurality of light-receiving elements which receives a reflected light from a read original D to read an image of the read original D and with a plurality of heat generating elements 9 which generates heat to form an image on recording paper P. In this case, a plurality of the heat generating elements 9 are placed in a column on one main side of 1st board 6, and an image sensor chip 12 in which a plurality of the light-receiving elements are formed is placed in a column on the other main side of the 1st board 6, at a position deviated from a position corresponding to a plurality of the heat generating elements 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading / writing head having both an image reading function and a printing function of a thermal transfer system or a thermal system.

[0002]

2. Description of the Related Art For example, in an image processing apparatus such as a facsimile apparatus, an image sensor having an image reading function and a thermal print head for recording a received image or an image read by the image sensor on a thermosensitive recording paper or the like. Are provided separately.

[0003]

In an image processing apparatus, if a head having both an image reading function and a function of recording an image on a thermosensitive recording paper or the like can be realized, the number of assembled parts of the facsimile apparatus as described above is reduced. And the space occupied by the head can be saved, and further downsizing of the facsimile apparatus and the like can be greatly expected. However, such an integrated head for image reading and writing has not existed conventionally.

Therefore, for example, a plurality of heat generating elements are provided in a row on one main surface of a substrate, and a plurality of heat generating element controlling integrated circuits for selectively generating heat according to print image data. Are provided on the other main surface of the substrate, a plurality of LED chips and a plurality of image sensor chips are provided in rows, respectively, and light from the LED chips is guided to the surface of the read original by a light guide plate, and the reflected light thereof is It is conceivable to realize an integrated image reading / writing head by adopting a configuration in which the light is focused by the rod lens array and incident on the image sensor chip.

According to such an integrated image reading / writing head, a light guide plate or a rod lens array is arranged between the other main surface of the substrate and the glass cover, and the reading is performed between the glass cover and the platen roller for reading. While holding the manuscript,
By separating the recording paper between the heating element on one main surface of the substrate and the platen roller for recording, the conveyance path of the read original and the conveyance path of the recording paper are divided on both sides of the integrated image reading / writing head. And the size of the image reading / writing integrated head can be reduced favorably. That is,
Since it is not necessary to set the transport path of the read original and the transport path of the recording paper adjacent to one surface of the integrated image reading / writing head, the size of the reading and recording in the sub-scanning direction can be reduced.

Generally, an image sensor chip has relatively sensitive temperature characteristics, and the input / output characteristics clearly change with temperature. However, in the image reading / writing integrated head as described above, since the heating element and the image sensor chip are separately arranged on both sides of the substrate, the heating element and the image sensor chip are located at positions where the heating element and the image sensor chip face each other with the substrate interposed therebetween. When the image sensor chip is installed, it is conceivable that the input / output characteristics of the image sensor chip greatly change due to the influence of heat generated by the heating element, and reading cannot be performed accurately. That is, since the temperature rise of the substrate due to the heating element is larger in a portion closer to the heating element, when the heating element and the image sensor chip are installed back to back across the substrate, the distance between the heating element and the image sensor chip becomes longer. Since the distance becomes a very small distance corresponding to the thickness of the substrate, the temperature rise of the image sensor chip is large, and the input / output characteristics of the image sensor chip are largely changed.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been conceived under such circumstances, and has both an image reading function as an image sensor and an image recording function as a thermal print head. An object of the present invention is to provide an image reading / writing head capable of reducing or eliminating a change in characteristics of a reading element caused by heat generation of a heating element.

In order to solve the above problems, the present invention takes the following technical measures.

According to the first aspect of the present invention, a plurality of light receiving elements for reading an image on a read document by receiving reflected light from the read document, and forming an image on a recording sheet by generating heat. An image reading / writing head having a plurality of heating elements, wherein a plurality of heating elements are provided in a row on one main surface of a first substrate, and a plurality of light receiving elements are provided on the other main surface of the first substrate. An image reading / writing head is provided, which is provided in a row at a position shifted from a position corresponding to a plurality of heating elements.

According to this image reading / writing head, a plurality of heating elements are provided in a row on one main surface of the first substrate, and a plurality of light receiving elements are provided on the other main surface of the first substrate. Are provided in a row at a position shifted from the position corresponding to the heating element, so that it has both an image reading function as an image sensor and an image recording function as a thermal print head, and furthermore, it is caused by heat generation of the heating element. Changes in the characteristics of the light receiving element can be reduced or eliminated. That is, since the heating element and the light receiving element are prevented from being back-to-back with the first substrate therebetween, the distance between the heating element and the light receiving element can be increased. Since the size can be reduced, a change in characteristics of the light receiving element can be reduced or eliminated.

As the plurality of light receiving elements, for example, an image sensor can be used, but it is not limited to this. The image sensor is a MOS image sensor or CC
Various types such as a D image sensor can be used.

As the plurality of heating elements, for example, a power supply-side electrode film and a ground-side electrode film are alternately brought into contact with a belt-shaped resistance film in a comb-tooth shape, and the resistance-film power supply-side electrode film and the ground-side electrode film are combined. It is possible to use a structure in which each of the sandwiched portions has a heating element, but the invention is not limited to such a configuration.

As the first substrate, for example, a ceramic substrate can be used, but it is not limited to this, and any substrate can be used as long as it can withstand the heat generated by the heating element.

As a light source for supplying the reflected light from the read original, for example, an LED chip can be used.
It is not limited to this. It is preferable that a light source such as an LED chip be provided on another substrate and mounted on the substrate, but it is also possible to mount the light source on the other main surface of the first substrate.

In order to guide the light from the light source to the read original and guide the reflected light from the read original to the light receiving element, for example, a transparent cover is attached to the case of the image reading / writing head, and the read original is placed along the transparent cover. , The light from the light source is radiated to the read original through the transparent cover, and the reflected light is focused by the rod lens array through the transparent cover and made incident on the light receiving element, but is not limited thereto. Not something.

According to a preferred embodiment, a plurality of light-emitting elements as light sources for reading are provided on a second substrate different from the first substrate.
And the first and second substrates are held by a case, and the case has at least a portion of the other main surface of the first substrate that abuts a position corresponding to the plurality of heating elements on the first substrate. It is composed of a heat absorbing member made of a material having a higher thermal conductivity than that of the heat absorbing member.

With this configuration, since the heat generated by the heat-generating element quickly moves from the substrate to the heat-absorbing member, the temperature rise of the substrate can be suppressed, and the characteristic change of the light-receiving element due to the heat, and the deformation and damage of the substrate can be further improved. Can be prevented. In addition, since the light emitting element is provided on the second substrate, the first substrate is not enlarged in size as compared with the case where the light emitting element is provided on the other main surface of the first substrate. The contact area between the other main surface and the heat absorbing member can be increased, and a change in the characteristics of the light receiving element due to heat can be sufficiently suppressed.

The case may be formed of, for example, a resin, and a heat absorbing member may be insert-molded in the resin, or the case may be made of a metal such as aluminum to make the entire case a heat absorbing member.

As the heat absorbing member, for example, a metal such as aluminum can be used, but it is not limited to this.

According to another preferred embodiment, the case is entirely formed of a heat absorbing member, and the heat absorbing member is manufactured using a process including extrusion molding.

With this configuration, the heat transmitted to the substrate due to the heat generated by the heat generating element can be quickly radiated to the atmosphere, and the temperature rise of the light receiving element can be suppressed extremely well. In addition, since the heat absorbing member as the case is manufactured using a process including extrusion molding, the production efficiency is good and the production cost can be reduced.

According to yet another preferred embodiment,
A heating element control integrated circuit for selectively causing the plurality of heating elements to generate heat is provided on one main surface of the first substrate at a position corresponding to the plurality of light receiving elements; Was coated with an opaque coating material.

With this arrangement, the coating material can effectively block the penetration of external light that passes through the first substrate from the outside of the image read / write head and enters the light receiving element, thereby deteriorating the reading accuracy due to the penetration of the external light. Can be prevented. In addition, since the invasion of external light is prevented by using the coating material of the integrated circuit for controlling the heating element, the production cost does not increase.
That is, it is necessary to reduce the thickness of the first substrate in order to reduce the size and weight of the image read / write head. For this reason, external light may enter the light receiving element through the first substrate. If the first substrate is coated with a coating material only to prevent the intrusion of the first substrate, the cost is required. However, if the penetration of external light is prevented by the originally required coating material of the heating element control integrated circuit, there is no increase in cost.

The coating material is preferably a black material, but is not limited to this. In short, any material can be used as long as it can block external light.

According to yet another preferred embodiment,
The input and output of signals and power to a heat-generating element control integrated circuit for selectively generating heat from a plurality of heat-generating elements and a light-receiving element control integrated circuit for sequentially extracting read image signals from the plurality of light-receiving elements, This is performed using one connector that sandwiches a part of the first substrate.

This is economical because only one connector is required.

[0027] Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic perspective view of an image read / write head 1 according to the present invention, and FIG. 2 is a sectional view taken along a direction orthogonal to the longitudinal direction of the image read / write head 1. And a case 2 having a predetermined longitudinal dimension. As shown in FIG. 2, the case 2 has a first recess 3 and a second recess 4 except for both ends in the longitudinal direction, and the opening of the second recess 4 is closed. Thus, the transparent cover 5 is attached.
The first substrate 6 is attached so as to close the opening of the first concave portion 3, and the second substrate 7 is attached inside the second concave portion 4. Second substrate 7
An LED chip 8 as an illumination light source is attached to one main surface at predetermined intervals in the longitudinal direction. The other main surface of the second substrate 7 is in contact with the case 2. On one main surface of the first substrate 6, the heating elements 9 are formed in a row near one side in the width direction and along the longitudinal direction.
The heating element control integrated circuits 10 are mounted in a row near the other side in the width direction and along the longitudinal direction. A black coating material 11 is coated near the mounting position of the heating element control integrated circuit 10 on one main surface of the first substrate 6, and the heating element control integrated circuit 10 is covered with the coating material 11. I have. An image sensor chip in which a plurality of light receiving elements and a light receiving element control integrated circuit for sequentially taking out read image signals from these light receiving elements are formed on one chip on the other main surface of the first substrate 6. 12
Are mounted in a row near one side in the width direction and along the longitudinal direction. A substantially half of the other main surface of the first substrate 6 near the other side in the width direction is in contact with the case 2. The heat-generating element control integrated circuit 10 and the image sensor chip 12 are arranged at a back-to-back position with the first substrate 6 interposed therebetween, and at a position corresponding to the heat-generating element 9 on the other main surface of the first substrate 6. Is in contact with case 2. Case 2 contains the first
A communication space for communicating the concave portion 3 with the second concave portion 4 is formed, and a rod lens array 13 as an optical lens is provided in the communication space. The image sensor chip 12 is located in a closed space formed by the case 2 and the first substrate 6. A connector 14 is detachably attached to the first substrate 6 at the center in the longitudinal direction and near the other side in the width direction. The connector 14 sandwiches the first substrate 6 in its thickness direction, and
Are in contact with both the pins connected to the wiring pattern on one main surface of the first substrate 6 and the pins connected to the wiring pattern on the other main surface of the first substrate 6.

The case 2 is made of a metal such as aluminum, for example, and has a function of holding the first substrate 6, the second substrate 7, the rod lens array 13, and the like. It also has a function as a heat absorbing member that absorbs heat transmitted to the first substrate 6 and discharges it to the atmosphere. This case 2 has holes 23 as shown in FIG.
Is formed by extrusion molding, and the holes 23 are machined except for both ends in the longitudinal direction of the case member 2a. Alternatively, as shown in FIG. 4, a pair of metal case members 2b and 2c are manufactured by extrusion molding, and both ends of the case members 2b and 2c in the longitudinal direction are connected by a metal bridging member 24. Can also be manufactured. The case members 2b, 2c and the bridging member 24 can be connected by, for example, welding.

The transparent cover 5 is made of, for example, glass or resin. The first substrate 6 is, for example, a ceramic substrate. The second substrate 7 is, for example, an epoxy substrate. The LED chip 8 functions as a light source that irradiates the read document D. The heating element 9 functions as a heat source for recording an image on the recording paper P. The specific configuration of the heating element 9 will be described later. Heating element control integrated circuit 1
Reference numeral 0 denotes a chip on which a heating element control circuit for selectively driving the heating element 9 is formed, which is die-bonded to one main surface of the first substrate 6 and is connected to one main surface of the first substrate 6. The wiring pattern (not shown) formed on the surface is connected by wire bonding. Coating material 1
Reference numeral 1 denotes an image sensor chip 12 that protects the heat-generating element control integrated circuit 10 and transmits through the first substrate 6.
To block external light incident on. Image sensor chip 12
A chip formed integrally with a plurality of light receiving elements for receiving reflected light from the read document D and outputting image signals, and a light receiving element control circuit for sequentially taking out image signals from these light receiving elements; It is die-bonded to the other main surface of one substrate 6 and connected to a wiring pattern (not shown) formed on the other main surface of first substrate 6 by wire bonding. The rod lens array 13
For example, it is made of glass or resin, and forms an image of the read original D at an equal size of an erect image on the light receiving surface of the image sensor chip 12. The connector 14 is connected to the integrated circuit 10 for controlling the heating element.
Input / output signals and a power supply for a heating element control circuit for selectively driving the heating element 9 formed on the chip and a light receiving element control circuit for sequentially extracting image signals from the light receiving elements formed on the image sensor chip 12. A cable (not shown) for transmission is connected.

For example, when a document having an A4 width is read at a main scanning density of 8 pixels / mm, it is necessary to arrange 1,728 light receiving elements in a line at equal intervals. Such a light receiving element is realized by arranging a plurality of image sensor chips 12 on each of which a plurality of light receiving elements are formed on the other main surface of the first substrate 6. For example, when using the image sensor chip 12 having 96 light receiving elements formed thereon, the 18 image sensor chips 12 are brought into close contact with each other in the longitudinal direction so that the pitch of all the light receiving elements is constant, and the first image sensor chip 12 is formed. It will be mounted on the other main surface of the substrate 6.

A reading platen roller 21 is disposed so as to face the upper surface of the transparent cover 5.
The document D to be read is guided on the transparent cover 5 by being backed up by the platen roller 21. The above configuration realizes a function as an image sensor that reads an image of the read document D guided on the transparent cover 5. That is, the light / dark image on the read original D along the read line L set on the transparent cover 5 is
Reflected on the two light receiving element rows,
A read image signal representing the amount of light received by each light receiving element is serially output.

A platen roller 22 for writing is arranged so as to face the heating elements 9 arranged in a row on one main surface of the first substrate 6.
The recording paper P, such as a thermal recording paper, is conveyed in such a manner that the recording paper P is pressed against the heating element 9 so that the recording paper P is backed up. The above configuration formed on one main surface of the first substrate 6 realizes a function as a thermal print head. That is, the heat-generating element control integrated circuit 10 drives the heat-generating elements 9 selected from the heat-generating dot row composed of a large number of heat-generating elements 9 for each print line in accordance with the recorded image data.

Hereinafter, a specific configuration of the heating element 9 will be described.
This will be described in more detail.

FIG. 5 is a front view of one main surface of the first substrate 6. On the one main surface of the first substrate 6, a large number of heating elements 9 are arranged near one side in the width direction. A plurality of heat generating element control integrated circuits 10 are arranged in a row near the other side in the width direction. The heating element control integrated circuit 10 is covered with a coating material 11.

FIG. 6 is a front view of the other main surface of the first substrate 6. On the other main surface of the first substrate 6, a plurality of image sensor chips 12 are located closer to the other side in the width direction. They are closely arranged in rows. Further, a connector 14 is attached to the central portion in the longitudinal direction of the first substrate 6 near the other side in the width direction. The connector 14 is connected to the image sensor chip 12.
A light-receiving element control circuit for sequentially taking out image signals from the light-receiving elements formed on the chip, an input / output signal of a heating element control circuit for selectively driving the heating element 9 formed on the chip of the heating element control integrated circuit 10, A cable (not shown) for transmitting power is connected.

FIG. 7 is an enlarged front view of a main part of one main surface of the first substrate 6 at both ends in the longitudinal direction. One main surface of the first substrate 6 is along one side edge. Thus, the heating element 9
Are formed in a straight line, and the heat-generating element control integrated circuit 10 for sharing and driving the heat-generating elements 9 by a predetermined number is provided on one side of the first substrate 6. Plural pieces are mounted along the other side edge of the main surface.

FIG. 8 is an enlarged front view of a part of the heating resistor 31, and a common electrode wiring 32 is formed outside the heating resistor 31 so as to extend in parallel with the heating resistor.
From this common electrode wiring 32, a comb-shaped common pattern 33 extends in the width direction of the first substrate 6 so as to extend under the heating resistor 31. Further, a comb-shaped individual electrode pattern 34 is inserted into a region between the common patterns 33. The base end of the individual electrode pattern 34 is extended to near one side of the integrated circuit 10 for controlling the heating element.
The output pads of the heat-generating element control integrated circuit 10 are connected by wire bonding.

Each heating element control integrated circuit 10 supplies a current to the selected individual electrode pattern 34 according to the recording image data input thereto. Then, in the heating resistor 31, a current flows in a region between the common patterns 33 located on both sides of the individual electrode pattern 34, and the region generates heat. That is, the heating resistor 31
As shown in detail in FIG. 8, is divided into small regions in the longitudinal direction by a comb-like common pattern 33 that extends underneath, and each divided region functions as a heating element 9.

In the above configuration, when reading the read original D, light emitted from the LED chip 8 is applied to the read original D via the transparent cover 5, and reflected light from the read original D passes through the transparent cover 5. Rod lens array 13 through
And is focused by the rod lens array 13,
The light enters a light receiving element formed on the image sensor chip 12. As a result, the read image signal is transmitted from the image sensor chip 12 to the outside of the image read / write head 1 via the wire bonding, the wiring pattern formed on the other main surface of the first substrate 6, the connector 14, and the cable (not shown). This means that the image has been taken out and one line of image has been read.
Then, the read original D is fed by one line in the direction of the arrow by the platen roller 21, and the same operation is repeated thereafter.

When an image is recorded on the recording paper P, a cable (not shown), a connector 14 and a wiring pattern formed on one main surface of the first substrate 6 are wire-bonded from outside the image reading / writing head 1. The recording image data is input to the heat-generating element control integrated circuit 10 through. As a result, the heating element controlling integrated circuit 10 selects the heating element 9 to be driven according to the input recording image data,
The individual electrode patterns 34 are selectively energized accordingly. In other words, the individual electrode pattern 34
, The heating resistor 31, the common pattern 33, and the common electrode wiring 32 to form a closed loop extending to the negative side of the power supply. As a result, the heating element 9 generates heat according to the recording image data, and an image for one line is recorded on the recording paper P.
Then, the recording paper P is fed by one line in the arrow direction by the platen roller 22, and the same operation is repeated thereafter.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an image reading / writing head according to the present invention.

FIG. 2 is a sectional view taken along a direction perpendicular to the longitudinal direction of the image reading / writing head according to the present invention.

FIG. 3 is an explanatory diagram of a manufacturing process of a case provided in the image reading / writing head according to the present invention.

FIG. 4 is an explanatory view showing another example of a process of manufacturing a case provided in the image read / write head according to the present invention.

FIG. 5 is a front view of one main surface of a first substrate provided in the image read / write head according to the present invention.

FIG. 6 is a front view of the other main surface of the first substrate provided in the image read / write head according to the present invention.

FIG. 7 is an enlarged front view of a main portion of a main surface of a first substrate provided in the image read / write head according to the present invention at both longitudinal ends.

FIG. 8 is an enlarged front view of a heating element portion of a first substrate provided in the image read / write head according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 image read / write head 2 case 5 transparent cover 6 first substrate 7 second substrate 8 LED chip 9 heating element 10 integrated circuit for controlling heating element 11 coating material 12 image sensor chip 13 rod lens array 14 connector

Claims (5)

[Claims] A plurality of light-receiving elements for reading an image on the read document by receiving reflected light from the read document; and a plurality of heat-generating elements for forming an image on a recording sheet by generating heat. An image read / write head, wherein the plurality of heating elements are provided in a row on one main surface of a first substrate, and the plurality of light receiving elements are arranged on the other main surface of the first substrate. Characterized by being provided in a row at a position shifted from a position corresponding to the heating element of
Image read / write head. 2. A plurality of light-emitting elements as light sources for reading are provided on a second substrate different from the first substrate, and the first and second substrates are held by a case, and the case is At least a portion of the other main surface of the first substrate abutting on a position corresponding to the plurality of heating elements is formed of a heat absorbing member made of a material having a higher thermal conductivity than the first substrate. The image reading / writing head according to claim 1. 3. The image reading / writing head according to claim 2, wherein the case is entirely formed of the heat absorbing member, and the heat absorbing member is manufactured by using a process including extrusion molding. 4. A heating element control integrated circuit for selectively causing the plurality of heating elements to generate heat is provided on one main surface of the first substrate at a position corresponding to the plurality of light receiving elements. 4. The image reading / writing head according to claim 1, wherein the heating element controlling integrated circuit is coated with a light-impermeable coating material. 5. A signal for a heating element control integrated circuit for selectively causing the plurality of heating elements to generate heat, and a light receiving element control integrated circuit for sequentially extracting read image signals from the plurality of light receiving elements. The image read / write head according to claim 1, wherein input / output of power and input / output of power are performed using one connector that sandwiches a part of the first substrate.