JP2003159837A - Print head and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a print head having a plurality of light emitting elements arranged in array in which an optimal image can be obtained by suppressing deterioration of an image being formed due to deterioration of each light emitting element, and thereby the lifetime of the print head can be prolonged. <P>SOLUTION: The print head 3 comprises a plurality of light emitting elements 71 arranged in array on a substrate 70, and a plurality of light receiving elements 72 arranged on the substrate 70 and receiving light from the plurality of light emitting elements. Preferably, the light emitting element 71 has an emission layer containing an organic matter and emits light by electroluminescence of the organic matter upon application of an electric field. An imaging apparatus X comprising the print head 3 is also provided. The imaging apparatus X comprises means for controlling emission of the light emitting element 71 based on the quantity of light being received by the plurality of light receiving elements 72. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head used when forming an image on a photosensitive recording medium by a photosensitive method and an image forming apparatus equipped with this print head.

[0002]

2. Description of the Related Art An electronic image taken by a digital camera or the like can be printed on plain paper by an inkjet method or a thermal transfer method using the digital data. On the other hand, it is also considered to record an image as digital data on a photosensitive film by a photosensitive method. In the photosensitive method, an image is formed through a process of exposing a photosensitive film and then developing it, so that an image with high resolution can be formed. Therefore, a digital camera having a built-in photosensitive print head and capable of printing an image immediately after photographing has been commercialized.

When an image is formed on a recording medium by a photosensitive method, for example, linear light extending in the main scanning direction is scanned in the sub scanning direction to irradiate the entire photosensitive film with light. As a print head for irradiating linear light, for example, a print head having a configuration in which a plurality of light emitting elements are arranged in a line on the substrate in the main scanning direction is used. As the light emitting element, a light emitting diode is generally used, but an organic EL light emitting element can also be used.
The organic EL light emitting element refers to an element which emits light by electroluminescence when an electric field is applied to a light emitting layer containing an organic substance.

[0004]

However, the light emitting element deteriorates with time and the amount of light emission decreases. In particular, the organic EL light emitting element is easily deteriorated due to the growth of impurities mixed in the light emitting layer and the infiltration of water into the light emitting layer. On the other hand, the plurality of light emitting elements do not deteriorate to the same extent with the passage of time, and there is a variation in the speed of deterioration among the individual light emitting elements. Therefore, if some of the plurality of light emitting elements have a significantly greater degree of deterioration than other light emitting elements (those with a small light emission amount), it is possible to irradiate the photosensitive film with appropriate linear light. become unable. In other words, when the print head is scanned in the sub-scanning direction to expose the entire photosensitive film, there is an under-exposed region extending in the sub-scanning direction on the photosensitive film, which forms Appears as a linear image on the image. At the same time, a print head that employs a light-emitting element that easily deteriorates, such as an organic EL light-emitting element,
It means short life.

The present invention has been devised under such circumstances, and in a print head in which a plurality of light emitting elements are arranged in a row, deterioration of a formed image due to deterioration of each light emitting element. The problem is to obtain a proper image while suppressing the printhead, and thus to prolong the life of the printhead.

[0006]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention takes the following technical means.

That is, the print head provided by the first aspect of the present invention comprises a substrate, a plurality of light emitting elements arranged in a row on the substrate, and a plurality of the light emitting elements arranged on the substrate. A plurality of light receiving elements for receiving light from the light emitting element.

In this structure, the amount of light emitted from each light emitting element can be monitored through a plurality of light receiving elements.
It is possible to control the light emission amount of each light emitting element based on the result. Therefore, even if, for example, a plurality of light-emitting elements that include a larger degree of deterioration than other light-emitting elements are included, the amount of electricity supplied to the light-emitting element that has a large deterioration is increased, It becomes possible to make the amount of light emission comparable to the other ones. As a result, it is possible to irradiate the photosensitive recording medium with appropriate linear light, and it is possible to eliminate the insufficiently exposed region in the photosensitive recording medium. This allows
The deterioration of the image formed on the photosensitive recording medium can be suppressed, and at the same time, the life of the print head can be extended.

In a preferred embodiment, the substrate is a transparent substrate, and the plurality of light emitting elements are arranged on the first surface of the substrate and opposite to the first surface of the substrate. The plurality of light receiving elements are arranged on the second surface such that the light receiving surface of the plurality of light receiving elements faces the second surface. .

In this structure, the light-receiving surface of the light-receiving element faces the light-emitting element side in the region close to the light-emitting element. Therefore, the amount of light received by the light receiving element more reflects the amount of light emitted from the light emitting element. As a result, the amount of light received by the light emitting element can be controlled appropriately.

In a preferred embodiment, the plurality of light receiving elements extend in the same direction as the row of the light emitting elements in a plan view of the substrate, and are arranged in a row offset from the row of the light emitting elements. It is located in.

In this structure, of the light emitted from the light emitting element, the light which does not directly contribute to the irradiation of light on the photosensitive recording medium is selectively received, and the amount of light emitted by the light emitting element is based on the light. Will be able to control. As a result, it becomes possible to control the light emission amount of the light emitting element without lowering the light irradiation efficiency with respect to the photosensitive recording medium.

In a preferred embodiment, the light emitting device has a light emitting layer containing an organic substance, and the organic substance is
It emits light by electroluminescence when an electric field is applied (organic EL light emitting element).

As described above, the organic EL light emitting element is
Deteriorates more easily than ED. Therefore, according to the present invention in which the light emission amount of the light emitting element can be controlled, the organic EL element is used as the light emitting element.
This is useful for print heads that employ L light emitting elements. Moreover, since the organic EL light emitting element consumes less power,
If the organic EL light emitting element is adopted, the power consumption of the print head can be reduced.

In a preferred embodiment, the plurality of light emitting elements are covered with a sealing portion made of an inorganic insulating material.

With this structure, the light emitting element can be protected from an external force. In addition, since the inorganic substance is less likely to absorb moisture than the organic substance, in the case where the light emitting element has an organic layer, it is possible to prevent the moisture from entering the light emitting element from the surrounding environment by the sealing portion. If the infiltration of water into the light emitting layer of the light emitting element can be suppressed, the deterioration of the light emitting element can be suppressed, and the life of the light emitting element and thus the print head can be extended. Such measures are useful for a print head that employs an organic EL light emitting element that is easily deteriorated by the infiltration of water into the light emitting layer.

The sealing portion may be provided by adhering an inorganic insulating plate, or may be provided by potting an inorganic insulating material and then firing or drying it.

According to a second aspect of the present invention, there is provided an image forming apparatus equipped with the print head according to the first aspect of the present invention, wherein the light emitting elements of the plurality of light receiving elements are based on the amount of light received by the plurality of light receiving elements. An image forming apparatus is provided, which is provided with a control unit that controls the amount of light emission.

With this configuration, the print head according to the first aspect of the present invention is provided, and the light emission amount of the light emitting element is controlled by the control means based on the light reception amount of the light receiving element. By controlling the amount of light emitted by the light emitting element, it is possible to eliminate an insufficiently exposed region in the photosensitive recording medium, and it is possible to optimize an image formed on the photosensitive recording medium.

In a preferred embodiment, the first information regarding the initial light emission amount of each of the light emitting elements and the second information regarding the light receiving amount of each of the light receiving elements acquired to control the light emission amounts of the plurality of light emitting elements. Based on the information, and further comprising a calculating means for calculating the change amount of the light emission amount in the light emitting element compared to the initial light emission amount, the control means, based on the calculation result in the calculating means, It is configured to control the amount of light emitted by the light emitting element.

With this configuration, the light emission amount of the light emitting element is controlled in accordance with the change amount of the light emission amount of the light emitting element compared with the initial light emission amount, that is, the deterioration amount of each light emitting element. Therefore, the light emission amount of the light emitting element can be kept constant with reference to the initial light emission amount, so that the light irradiation to the photosensitive recording medium can be appropriately performed for a long period. As a result, the image formed on the photosensitive recording medium can be homogenized for a long period of time.

As the initial light emission amount, for example, one measured at a light emitting portion (a portion for emitting light from a plurality of light emitting elements to the outside) in the print head can be adopted. Then, the amount of light emitted from the light emitting element can be controlled according to the amount of light actually applied to the photosensitive recording medium. In this case, the third information regarding the amount of light received by the light receiving element is acquired at the same time as the measurement of the initial amount of light emission, and the correlation between the first information and the third information is defined and calculated. In the means, it is preferable that the change amount of the light emission amount of the light emitting element is calculated based on the second information and the correlation. Of course, the initial light emission amount may be set based on the amount of light received by the light receiving element.

Here, as the timing of measuring the initial light emission amount,
For example, when the initial light emission amount is measured at the light emitting portion, there are an inspection after assembling the print head and an initial setting before shipping. When setting the initial amount of light emission based on the amount of light received by the light receiving element, the timing for measuring the amount of light required for setting the initial amount of light emission should be in addition to the time point exemplified above, in which the user uses the image forming apparatus. In this case, the initial setting can be given. Of course, it is also possible to measure the initial light emission amount at a time other than the exemplified time point, or to measure the light amount necessary for setting the initial light emission amount.

It is preferable that the calculation means is configured to intermittently calculate the amount of change (deterioration amount) in the amount of light emitted from the plurality of light emitting elements. The timing of calculating the deterioration amount may be, for example, when the user issues a print instruction or when the power of the image forming apparatus is turned on. Of course, the deterioration amount may be calculated every time a specific time elapses. The calculation of the deterioration amount in this case is preferably performed within the time range in which the image forming apparatus is powered on.

The control means and the arithmetic means may be provided in the print head or may be provided separately from the print head.

When a color image is printed on the photosensitive recording medium, the light emitting elements include a red light emitting portion, a green light emitting portion, and a blue light emitting portion, which are configured to emit light individually. Used. The light emitting section for each color may emit white light and separate it into red light, green light, and blue light using a color filter. However, when the light passes through the color filters, the light utilization efficiency deteriorates, so from the viewpoint of power consumption, the light emitting units of the respective colors emit red light without passing through the color filters.
It is preferable to be configured to emit green light or blue light by itself.

When the light emitting element has a light emitting section for each color, the calculating section individually calculates the deterioration amount of the light emitting quantity for each light emitting section based on the light receiving quantity of the plurality of light receiving elements, and the control means. Is preferably configured to individually control the light emission amount for each light emitting unit.

With this configuration, since the amount of light emission is controlled for each light emitting portion for each color, color printing can be appropriately performed.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

As shown in FIGS. 1 and 2, the image forming apparatus X according to the present invention comprises a housing 1, a film pack 2,
It has a print head 3 and a drive circuit 4.

The housing 1 has an opening 10 as shown in FIG.
The opening 10 can be opened and closed by a lid 11. The lid 11 is provided with a pair of convex portions 12. A discharge port 14 for discharging the exposed and developed photosensitive film 5 (see FIGS. 3 and 4) is formed on the side surface 13 of the housing 1. Further, in the housing 1, FIG.
The push bar 15 and the platen roller 16 are arranged as shown in FIG.

The film pack 2 contains a plurality of photosensitive films 5 inside a case 20 as shown in FIG. The photosensitive film 5 is placed on the support base 21. The support base 21 is biased by a leaf spring member 22.

As shown in FIGS. 1 and 3, the case 20 is formed with first to third openings 23, 24, 25 for moving the push bar 15 in the directions of arrows B1, B2 in FIG. An allowance notch 26 is provided. The print head 3 is disposed in the first opening 23. The print head 3 may be configured to move the first opening 23 in the directions of arrows B1 and B2, or may be fixed to the housing 1. The second opening 24 is the convex portion 1 of the lid 11.
It is provided in the part corresponding to 2. That is, the lid 11
When the opening 10 is closed by, the protrusion 12 is inserted into the case 20 through the second opening 24 as shown in FIG. As a result, the first opening 23 is
The pressing force to the side acts. On the other hand, the third opening 25
Is provided on the side surface of the case 20, and the photosensitive film 5 is discharged to the outside of the case 20 through the third opening 25. The third opening 25 is covered with a curtain 27, and the entry of dust from the third opening 25 into the case 20 is suppressed.

The photosensitive film 5 has a form in which a photosensitive layer 51 and a transparent cover 52 are laminated on a base material 50 as shown in FIG. The peripheral edges of the base material 50, the photosensitive layer 51, and the transparent cover 52 are covered with an adhesive sheet 54 with the developer holding pack 53 wrapped around the ends.

As can be seen from FIG. 1, such a film pack 2 can be freely taken in and out of the housing 1 through the opening 10. When all the photosensitive films 5 accommodated in the film pack 2 are used, the used film pack 2 is taken out and a new film pack 2 is used.
You can put on.

As shown in FIG. 3, the push bar 15 pushes out the photosensitive film 5 from the film pack 2, and the platen roller 16 conveys the photosensitive film 5 while pulling it out from the film pack 2, and through the discharge port 14. It is for discharging the photosensitive film 5 to the outside of the housing 1. The platen roller 16 further exerts a pressing force on the developer pack 53 (see FIG. 4) of the photosensitive film 5 when the photosensitive film 5 passes through the platen roller 16, and pushes out the developer from the developer pack 53. Also plays a role of expanding the entire surface of the photosensitive layer 51.

As shown in FIGS. 5 and 6, the print head 3 has a structure in which the light emitting element array 7, the rod lens array 8A and the prism 8B are held by the frame 6.

The frame 6 has a U-shaped mounting portion 60,
First extending in the directions A1 and A2 (main scanning direction) of FIG.
A holding portion 61 and a second holding portion 62 are provided. The organic EL light emitting element array 7 is mounted on the mounting portion 60. The first holding portion 61 has an inclined surface 61a inclined by 45 degrees, and the reflection member 63 is in close contact with the inclined surface 61a.
Is retained. The reflecting member 63 is preferably a mirror surface so that light can be totally reflected on the surface thereof, and the surface is made of, for example, aluminum.

On the other hand, the rod lens array 8A is held by the second holding portion 62. The rod lens array 8A is
A holder 81 having a plurality of through holes 80 formed therein has a configuration in which a rod lens 82 is held in the through hole 80. The axis of each rod lens 82 extends in the directions of arrows B1 and B2 (sub scanning direction) in FIG.
A plurality of rod lenses 82 are arranged side by side in the main scanning directions A1 and A2. In the present embodiment, the rod lens 82 is configured to form a normal-ratio image with equal magnification.

The side portion of the frame 6 is open toward the sub-scanning direction B1 side, and the prism 8B is held in this portion.
The prism 8B is fixed to the frame 6 by fitting the convex portion 83 provided on the prism 8B into the concave portion 64 provided on the frame 6. Prism 8B
Has a light incident surface 84, a light reflecting surface 85, and a light emitting surface 86. In the prism 8B, the light reflected by the reflecting member 63 is incident on the light incident surface 84 and then reflected by the light reflecting surface 85 so that the traveling direction is changed by 90 degrees.
The light is emitted from the light emitting surface 86. Such a prism 8B
Is formed of a material having a refractive index larger than that of air, such as transparent glass or acrylic resin.

As shown in FIGS. 5 to 7, the organic EL light emitting element array 7 has a long rectangular transparent substrate 70, a plurality of organic EL light emitting elements 71 provided on the upper surface 70a of the transparent substrate 70, and a transparent substrate 70. Has a plurality of light receiving elements 72 and a plurality of drive ICs 73 provided on the lower surface 70b of the. The drive IC 73 controls the supply of various signals such as image data and clock pulse signals and the supply of electric power.

As shown in FIG. 7, the plurality of organic EL light emitting elements 71 are arranged in rows in the longitudinal direction (main scanning direction) A1 and A2 of the transparent substrate 70. These organic EL light emitting elements 71 are covered with a sealing portion 74 as well shown in FIG. The sealing portion 74 is provided by bonding a glass plate with an adhesive 75, for example. The sealing portion 74 may be formed by applying glass paste or the like and then baking it, or by applying molten or softened glass and then drying it. If such a sealing portion 74 is provided, the organic EL light emitting element 71 is protected from external force, and since the glass that is an inorganic substance is less likely to absorb moisture than the organic substance, the organic EL from the surrounding environment is protected.
The entry of moisture into the light emitting element 71 is suppressed.

As shown in FIG. 7, each organic EL light emitting element 71 has a transparent substrate 70 in the lateral direction (sub-scanning direction) B1, B.
It has a red light emitting portion 71R, a green light emitting portion 71G, and a blue light emitting portion 71B, which are arranged side by side. These organic EL
The light emitting element 71 (light emitting portions 71R, 71G, 71B) includes a plurality of anodes 76 and an organic layer (not shown) on the transparent substrate 70.
And three cathodes 77R, 77G, and 77B are laminated.

In the plurality of anodes 76, the portions extending in the longitudinal direction (main scanning direction) A1, A2 of the transparent substrate 70 are the transparent substrates 7 in the plurality of cathodes 77R, 77G, 77B.
The portion extending in the lateral direction of 0 (sub-scanning direction) B1 and B2 intersects, and these intersecting portions intersect the red light emitting portion 71.
R, a green light emitting portion 71G and a blue light emitting portion 71B are configured. These light emitting parts 71R, 71G, 71B
Are configured to emit light individually according to the energization states of the anode 76 and the cathodes 77R, 77G, 77B selected by the drive IC 73. The anode 76 is transparently made of ITO or the like, while the cathodes 77R, 77G, 77B are made of aluminum or the like and have high reflectivity. Therefore, the light from the light emitting portions 71R, 71G, and 71B is emitted from the lower surface 70b of the transparent substrate 70 via the transparent substrate 70 as well shown in FIG.

The organic layer has a light emitting layer containing a light emitting substance made of an organic material. Light emitting parts 71R, 71G, 71
B can be configured to emit red light, green light, or blue light by itself, depending on the type of luminescent substance used. Of course, it is also possible to configure the light emitting units 71R, 71G, and 71B so as to emit red light, green light, or blue light by using a color filter while emitting white light in the light emitting layer. The organic layer is composed of a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injecting layer when the light emitting substance contained in the light emitting layer has a low molecular weight. When the light emitting substance contained in the light emitting layer has a high molecular weight, the organic layer may be composed of only the hole transport layer and the light emitting layer. Of course, depending on the kind of the luminescent substance used, the organic layer may be configured as a two-layer structure including an electron transport layer and a light emitting layer, or a three layer structure including a hole transport layer, an electron transport layer and a light emitting layer.

As shown in FIG. 6, the driving IC 73 is mounted face down so that the terminals of the driving IC 73 are electrically connected to the corresponding ends of the anode 76. As shown in FIG. 7, the driving IC 73 and the transparent substrate 70
A wiring 79 is patterned between the long edge 70c and the long edge 70c. The end of this wiring 79 is electrically connected to the corresponding terminal of the drive IC 73, as expected from FIGS. 6 and 7.

On the other hand, the plurality of light receiving elements 72 are the light emitting elements 7
Although not shown in the drawing, it is configured to be arranged in rows in the longitudinal direction (main scanning direction) A1 and A2 of the substrate 70. The outputs from the plurality of light receiving elements 72 are sent to the arithmetic unit 43 as described later, and the light emission amount of the light emitting elements 71 (light emitting units 71R, 71G, 71B) is controlled based on the arithmetic result of the arithmetic unit 43. To be done.

Each light receiving element 72 is composed of, for example, a photodiode or a phototransistor.
The light receiving element 72 is mounted in a face-down manner so that its light receiving surface 72a faces the lower surface 70b of the transparent substrate 70. The rows of the light receiving elements 72 are arranged so as to extend in the same direction as the rows of the plurality of light emitting elements 71 in the plan view of the transparent substrate 70 and to be arranged in a row shape deviated from the rows of the plurality of light emitting elements 71. ing. A plurality of light receiving elements 72
Is the upper surface 70a of the transparent substrate 70 via wiring (not shown) and through holes formed on the lower surface 70b of the transparent substrate 70.
Is connected to the wiring 79 formed on.

In the present embodiment, the light receiving element 72
In the region close to the light emitting element 71, the light receiving surface 72a of the light receiving element 72 faces the light emitting element 71 side. Therefore, the amount of light received by the light receiving element 72 more reflects the amount of light emitted by the light emitting element 71. By offsetting the row of the light receiving elements 72 from the row of the light emitting elements 71, the light emitted from the light emitting elements 71 that does not directly contribute to the light irradiation to the photosensitive film 5 is selectively received. Then, the amount of light emitted from the light emitting element 71 can be controlled based on the light. As a result, the light emission amount of the light emitting element 71 can be appropriately controlled without reducing the light irradiation efficiency of the photosensitive film 5.

The wiring 79 and the cathodes 77R, 77G,
The end of 77B is connected to the flexible cable 9 as shown in FIG. The flexible cable 9
A wiring 91 is patterned on a flexible substrate 90 having an insulating property by vapor deposition or sputtering. The flexible cable 9 causes the print head 3 to output information regarding the amount of light received by the plurality of light receiving elements 72, and also supplies power and various signals to the drive IC 73.

In the print head 3 described above, as shown in FIG. 6, the light from the light emitting portions 71R, 71G and 71B is transmitted through the transparent substrate 70 and emitted toward the reflecting member 63. The light reaching the reflecting member 63 is reflected by the reflecting member 63.
Then, the light is incident on the rod lens array 8A after being totally reflected and bent in the traveling direction by 90 degrees. The light that has entered the rod lens array 8A passes through each rod lens 82 and then enters the prism 8B through the light incident surface 84.
The light incident on the prism 8B is bent in the traveling direction by 90 degrees at the light reflecting surface 85, travels downward in the prism 8B, and then exits via the light emitting surface 86. This light is
An image is formed on the photosensitive film 5, and the photosensitive film 5 is irradiated with linear light.

The drive circuit 4 shown in FIG. 2 is for controlling the operation of the print head 3 and has an input / output port 40, a control section 41, a storage section 42 and an arithmetic section 43.

The input / output port 40 is used when data corresponding to an image to be printed is input from the outside of the image forming apparatus X.

The control unit 41 controls each of the light emitting units 71R, 71G, 71B based on the amount of light received by the plurality of light receiving elements 72.
Has the role of controlling the amount of light emitted.

The storage unit 42 includes the light emitting units 71R, 71G,
The first information regarding the initial light emission amount for each 71B is stored. The initial light emission amount is, for example, the light emitting surface 8 of the prism 8B.
No. 1 measured based on the received light amount at this time.
Information is determined. The timing of measuring the initial light emission amount may be, for example, an inspection after assembling the print head 3 or an initial setting before shipping. Of course, the initial light emission amount may be set based on the amount of light received by the light receiving element 72. In this case, the timing of measuring the amount of light necessary for setting the initial light emission amount can be the time of initial setting when the user uses the print head, in addition to the time point exemplified above. Of course, it is also possible to measure the initial light emission amount at a time other than the exemplified time point, or to measure the light amount necessary for setting the initial light emission amount.

The calculation section 43 is configured to detect the first information and the light emitting section 71.
Based on the second information on the amount of light received by each light receiving element 72 acquired to control the amount of light emitted by each of R, 71G, and 71B, each light emitting unit 71R, 71G, which is compared with the initial amount of light emitted,
The change amount (deterioration amount) of the light emission amount for each 71B is individually calculated. The calculation unit 43 acquires, for example, third information regarding the amount of light received by the light receiving element 72 at the same time as when the initial amount of light emission is measured, and the correlation between the first information and the third information is calculated for each light emitting unit 71R. , 71G, 71B, and the change amount of the light emission amount for each of the light emitting units 71R, 71G, 71B is individually calculated based on this correlation and the second information. In this case, the correlation is stored in the storage unit 42.

To form an image on the photosensitive film 5 in the image forming apparatus X, the print head 3 is used to form an image on the photosensitive layer 51 (see FIG.
Exposure), and then developing it. The exposure by the print head 3 is performed based on the print instruction from the user.

In the present embodiment, when there is a print instruction, the exposure is performed on the photosensitive layer 51 (see FIG. 4).
The calculation necessary for controlling the light emission amount in each of the light emitting units 71R, 71G, 71B is performed. As described above, the calculation is individually performed for each of the light emitting units 71R, 71G, 71B, and the degree of deterioration of each of the light emitting units 71R, 71G, 71B is grasped.

The calculation of the degree of deterioration in the light emitting portions 71R, 71G, 71B may be performed when the power of the image forming apparatus X is turned on, and, of course, the calculation is automatically performed at each elapse of a specific time. You may When the calculation is performed each time the specific time elapses, it is preferable to perform the calculation within the time range in which the power of the image forming apparatus X is turned on.

The exposure of the photosensitive layer 51 (see FIG. 4) is performed by scanning the linear light from the print head 3 in the direction of arrow B1 in FIG. The linear light irradiation is separately performed for the same light irradiation line for the three colors of red light, green light, and blue light. At the time of exposure, the light emitting portions 71R, 71G, 7 where deterioration is recognized as compared with the initial light emission amount
For 1B, the control unit 41 increases the energization amount to the light emitting units 71R, 71G, and 71B according to the deterioration amount, or the light emitting units 71R, 71G, and 71B.
The pulse width (application time) of the applied voltage is increased. As a result, all the light emitting parts 71R, 71G, 71B
In, the amount of light emission is almost the same as the initial amount of light emission.

On the other hand, the developing process of the photosensitive film 5 is performed as shown in FIG.
As shown in FIG. 5, this is performed in the process of conveying the exposed photosensitive film 5. The exposed photosensitive film 5 is
By moving the push bar 15 in the arrow B2 direction in FIG. 3, the push bar 15 can be moved in the B2 direction. As a result, the front end portion of the photosensitive film 5 is moved to the second opening 25 of the case 20.
Is discharged from. When the leading end of the photosensitive film 5 reaches the platen roller 16, the rotation of the two platen rollers 16 causes the photosensitive film 5 to be conveyed between the platen rollers 16. Since the developing solution holding portion 53 (see FIG. 4) is provided at the front end portion of the photosensitive film 5, a pressing force acts on the developing solution holding portion 53 when passing between the platen rollers 16. As a result, the developing solution is pushed out, and the developing solution is discharged from the front end side of the photosensitive layer 51 (see FIG. 7).
Soak on both sides. Since the photosensitive film 5 passes between the platen rollers 16, the developing solution is spread to the rear end side of the photosensitive layer 51 (see FIG. 4) in the process. And
When the photosensitive film 5 has completely passed through the platen roller 16, the developing solution spreads over the entire photosensitive layer 51 (see FIG. 4), and the developing process of the photosensitive layer 51 (see FIG. 4) ends. The photosensitive film 5 that has undergone the development process is conveyed to the platen roller 16 to be discharged through the discharge port 14 of the housing 1.
Emitted from.

In the present embodiment, for the light emitting parts 71R, 71G, 71B which are found to be deteriorated compared to the initial light emitting amount, the light emitting amount is adjusted by the control part 41 so that the light emitting parts 71R, 71G of the same color. , 71B, the variation in the amount of light emission is eliminated. As a result, it is possible to irradiate the photosensitive film with linear light having a uniform light intensity distribution, and it is possible to eliminate an underexposed region in the photosensitive film 5. Thereby, deterioration of the image formed on the photosensitive film 5 can be suppressed. In addition, each light emitting portion 71R, which is compared with the initial light emission amount,
Each of the light emitting units 71 corresponding to the deterioration amount in 71G and 71B.
If the light emission amounts of R, 71G, and 71B are controlled, the light emission amounts of the light emitting units 71R, 71G, and 71B can be maintained constant with the initial light emission amount as a reference. Therefore, the light irradiation on the photosensitive film 5 can be appropriately performed for a long period of time. As a result, the image formed on the photosensitive film 5 can be homogenized for a long period of time. In particular, when using the organic EL light emitting element 71 which is easily deteriorated, the light emitting portions 71R, 71G, 71
It is useful to control the light emission amount in B. In addition, if the light emission amount is individually controlled for each of the light emitting units 71R, 71G, and 71B, color printing can be appropriately performed.

In the present embodiment, the image forming apparatus in which the photosensitive film is mounted as a film pack in which the photosensitive film is housed has been described, but the image forming is configured so that only the photosensitive film is sequentially added. The present invention can also be applied to an image forming apparatus configured to convey a photosensitive film in close contact with a print head by an apparatus or a platen roller.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an example of an image forming apparatus according to the present invention.

FIG. 2 is a block diagram of the image forming apparatus shown in FIG.

FIG. 3 is a sectional view of a main part of the image forming apparatus shown in FIG.

FIG. 4 is a sectional view of a photosensitive film.

5 is an exploded perspective view of a print head of the image forming apparatus shown in FIG.

6 is a cross-sectional view of the printhead shown in FIG.

FIG. 7 is a plan view and an enlarged view of main parts of a light emitting element array of the print head shown in FIGS. 5 and 6.

[Explanation of symbols]

X image forming device 3 print head 41 Control unit 43 Operation part 5 Photosensitive film 70 Transparent substrate 70a Top surface (of transparent substrate) 70b Lower surface (of transparent substrate) 71 light emitting element 71R Red light emitting part 71G green light emitting part 71B Blue light emitting section 72 Light receiving element 72a Light receiving surface (of light receiving element) 74 Sealing part A1, A2 main scanning direction B1, B2 Sub-scanning direction

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Claims (10)

[Claims] 1. A substrate, a plurality of light emitting elements arranged in a row on the substrate, and a plurality of light receiving elements arranged on the substrate and for receiving light from the plurality of light emitting elements. A print head, comprising: 2. The substrate is a transparent substrate, and the plurality of light emitting elements are disposed on a first surface of the substrate, and a second surface of the substrate opposite to the first surface. The light receiving element is configured to emit light toward a surface, and the plurality of light receiving elements are arranged on the second surface such that a light receiving surface thereof faces the second surface. Printhead as described. 3. The plurality of light receiving elements extend in the same direction as the rows of the plurality of light emitting elements in a plan view of the substrate,
The print head according to claim 2, wherein the print heads are arranged so as to be arranged in a row deviated from the row of the light emitting elements. 4. The light emitting device according to claim 1, wherein the light emitting element has a light emitting layer containing an organic substance, and the organic substance emits light by electroluminescence when an electric field is applied. Printhead as described. 5. The print head according to claim 1, wherein the plurality of light emitting elements are covered with a sealing portion made of an inorganic insulating material. 6. An image forming apparatus comprising the print head according to claim 1, wherein the light emitting amount of the light emitting elements is controlled based on the light receiving amounts of the plurality of light receiving elements. An image forming apparatus comprising a control means. 7. A first method relating to an initial light emission amount of the light emitting device.
Based on the information and the second information regarding the amount of light received by each of the light receiving elements acquired to control the amount of light emitted by the plurality of light emitting elements, the amount of light emitted from the light emitting element compared to the initial amount of light emitted is compared. The calculation means for calculating a variation amount is further provided, and the control means is configured to control a light emission amount of the light emitting element based on a calculation result of the calculation means. Image forming device. 8. The print head has a light emitting portion for emitting light from the plurality of light emitting elements, and the initial light emission amount is that measured by the light emitting portion. The image forming apparatus according to claim 7, which is provided. 9. The third information relating to the amount of light received by the light receiving element is acquired at the same time as the measurement of the initial amount of light emission, and the correlation between the first information and the third information is defined. 9. The image forming apparatus according to claim 8, wherein the calculation unit is configured to calculate a change amount of the light emission amount of the light emitting element based on the second information and the correlation. 10. The light emitting element has a red light emitting portion, a green light emitting portion, and a blue light emitting portion, and each light emitting portion can be individually driven, and the control means includes: 10. The light emitting amounts of the red light emitting portion, the green light emitting portion, and the blue light emitting portion are individually controlled based on the light receiving amounts of the plurality of light receiving elements. The image forming apparatus described.