JPH03230571A - Light source for high-density optical printer - Google Patents

Abstract

PURPOSE:To make highly uniform, high-density and high-quality printing by monolithically integrating a side-incident type light receiving element in a state where the element is electrically and spatially isolated from a light emitting diode array by means of an isolated groove and monitoring the optical output of each light emitting diode. CONSTITUTION:A side-incident type light receiving element 313 which is electrically and spatially isolated from each light emitting diode in a light emitting diode array by means of the first isolating groove 38-1 and monitors the optical output of each light emitting diode is formed by integration adjacent to each light emitting diode on a substrate on which the light emitting end face 3120 of the array is formed with the element 313 being on the opposite side to the end face 3120. An electrode 311 of the second conductivity type is formed on a layer 39 of the second conductivity type in the upper section of the element 313 and an electrode 37 of the first conductivity type 37 is formed on the rear surface of a substrate 36 of the first conductivity type corresponding to the layer 39. When such printer light source is used, the light emitted from the side face of the diodes opposite to the end face 3120 is made incident to the element 313 through the groove 38-1 and monitoring signal of the optical output of each diode can be obtained. Therefore, highly uniform high quality and high-density printing can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a high-density optical printer light source that uses a light emitting diode as a writing means on a photoreceptor.

(Prior Art) Research is being conducted on light emitting diode arrays with the aim of applying them to light sources for optical printers and the like that employ an electrophotographic printing method. Here, the light emitting diode array is composed of a self-luminous array element, which causes the light emitting diode array to emit light in response to an image signal, and forms an electrostatic latent image on the surface of the photoreceptor with a 1-magnification imaging element, thereby forming an electrostatic latent image using an electrophotographic method. This is used to print characters. Since the light emitting diode array has no moving parts and has few supporting parts, when used in the head of such an optical printer, the print head can be made smaller. In addition, it is self-luminous, has a high extinction ratio, and provides good contrast5.Furthermore, it is possible to use longer lengths by connecting chips, and it is also possible to support higher speeds by increasing the output of light-emitting diodes. You can make a profit. In this case, the light emitting diode array used is a surface emitting type light emitting diode array in which a large number of square light emitting parts are arranged in a predetermined direction in a plane parallel to the substrate surface,
There is an edge-emitting type light emitting diode array, etc., which can obtain a large number of light outputs arranged in a predetermined direction from an end face perpendicular to the substrate surface.

First, the basic structure of a single-surface light emitting diode array, as shown in Figure 7, has been reported (Proceedings of the National Conference of the Telecommunications Division of the Institute of Electronics and Communication Engineers, 1981, pp. 1-211). reference). In such a surface-emitting type light emitting diode array, in many cases, both ends of one light emitting part are used to equalize the intensity of the light output obtained from the light emitting part 1 within the light emitting surface.

Alternatively, the electrode 11 is formed around it. In this way, since the light emitting part from which light output is taken out and the electrode exist on the same plane, the width required per unit element is the sum of the width of the light emitting part, the width of the electrode, and the width of the element isolation region. For example, 60Qdpi (dots per 1n
ch) Forming the light emitting parts at high density as described above
It is extremely difficult.

Furthermore, there is a large variation in the light emitting output of each light emitting diode in a surface-emitting light emitting diode array, with values ranging from ~±40% within the same chip to ~±50% between chips.
%. This variation also has the drawback of causing large differences in the size of printed dots and print density. Such large variations in the light emitting output of each light emitting diode in the light emitting diode array are caused by variations in the characteristics of the compound semiconductor materials that make up the light emitting diode array, variations in the layer thickness of the laminated structure, and even the heat dissipation characteristics of the elements. This is caused by variations in the mounting form, etc. 5 It is impossible to realize a practical light emitting diode array for a high-density optical printer unless some kind of means is taken to correct variations in optical output.

Next, as an edge-emitting type light emitting diode array, for example, there is one as shown in FIG.
(See Publication No. 373). In this example.

A plurality of light emitting parts 2 are formed in a laminated structure on a substrate, and these light emitting parts are separated by separation grooves 3 formed in a plane parallel to the substrate surface in a direction perpendicular to its end surface. ,
electrically and spatially separated. In such an edge-emitting type light emitting diode array, the light emitting part 2 from which light output is taken out and the electrodes 21 and 25 are not on the same plane, and the width required per unit element is the width of the light emitting part and the element isolation area. For example, it is possible in principle to form a high-density light emitting section of 60 Qdpi or more.

Therefore, it can be said that an edge-emitting type light-emitting diode array is suitable as a light-emitting diode array for a high-density optical printer.

(Problem to be solved by the invention) However, even in an edge-emitting type light-emitting diode array having such characteristics, there is a large variation in the light emission output of each light-emitting diode within the light-emitting diode, and the value varies within the same chip. So ~±40%, between chips~
It reaches as much as ±50%. This variation also has the drawback of causing large differences in the size of printed dots and print density. For this reason, a light-emitting diode array for optical printers that is capable of high-quality printing with high density, such as 600 dpi or more, and high uniformity in print dot size and print density, has not been realized to date. There wasn't.

(Problem to be solved by the invention) The present invention aims to realize high-density, high-quality printing.

For example, a light emitting diode array that can form light emitting parts at a high density of 600 dpi or more, eliminates the above drawbacks, and enables high quality printing with high uniformity in print dot size and print density. The purpose is to capture and provide a high-density optical Bunter light source using

(Means for Solving the Problems) In order to achieve the above object, 1. In the high-density optical printer light source of the present invention, the light emitting diode array is configured to emit light from the side surface of the element which is not parallel to the surface containing the active layer of each light emitting diode. The edge-emitting type light-emitting diode is electrically and spatially separated from the edge-emitting type diode array by a first separation groove, and the side-incidence light is incident from the side surface of the element that is not parallel to the surface containing the active layer. A type light-receiving element is monolithically integrated on the same substrate as the edge-emitting type light-emitting diode to constitute an integrated type light-emitting diode array,
By making the light of the edge-emitting type light-emitting diode enter the side-illuminated light receiving element, the light output of each light-emitting diode of the edge-emitting type light-emitting diode is adjusted according to the magnitude of the light output of the edge-emitting type light-emitting diode. The control monitor signal was obtained from the side-illuminated light receiving element.

Here, it is preferable from the viewpoint of manufacturing that the edge-emitting type light emitting diode and the side-illuminated type light receiving element are configured with the same laminated structure.

Further, the side-illuminated light-receiving element can also be configured so that -light-receiving element light or light from a plurality of the edge-emitting light-emitting diodes enters the side-illuminated light-receiving element.

Further, side-illuminated light receiving elements and edge-emitting light-emitting diodes are formed in one-to-one correspondence, and for each light-receiving element of the side-illuminated light receiving element, a light-emitting diode in the edge-emitting light emitting diode array is formed. It is also possible to configure so that only i light beams are incident. Embodiment 1 (See FIGS. 1 and 2) FIG. 1 shows a printer light source using an integrated light emitting diode array according to the present invention, viewed diagonally from above on the light emitting end surface. FIG. 2 shows a longitudinal section in the direction of the light emission axis. The light emitting section of this printer light source is composed of an edge emitting type light emitting diode (312).

This edge-emitting type light emitting diode has a first conductivity type substrate 36.
A first conductivity type cladding layer 35, an active layer 34, which is a light emitting layer, are formed on top of the first conductivity type cladding layer 35, and an active layer 34, which is a light emitting layer. It is formed of a laminated structure (double heterostructure) consisting of a plurality of layers including a second conductivity type cladding layer 33 and a cap layer 32. A second separation groove 38-2 is formed perpendicularly to the substrate surface of the first conductivity type substrate 36 from the surface of this laminated structure, that is, the top surface of the camp layer, and reaches the substrate, and this separation groove allows the light emitting diode to Each light emitting diode in the array is electrically isolated. Further, the light emitting end face of each light emitting diode is formed perpendicular to the substrate surface.

Further, a second conductivity type electrode 31 is formed on the cap layer 32 of each of these light emitting diodes, and a first conductivity type electrode 37 is formed on the back surface of the first conductive substrate 36. .

In such a configuration, any second conductivity type electrode 31 and the first
By passing a predetermined forward current between the conductivity type electrodes 37, light output 314 can be obtained from the light emitting diodes at any position within the light emitting diode array. On the same substrate on the side opposite to the light emitting end surface 3120 of the light emitting diode array, each light emitting diode in the light emitting diode array is electrically and spatially separated by a first separation groove 38-1, and the light of each light emitting diode is separated. A side-illuminated light receiving element 313 for monitoring the output is integrally formed adjacent to each light emitting diode. This light receiving element has a first conductivity type layer 310.
It is composed of a laminated structure of a second conductivity type calendar 39,
Light from the light emitting diode enters from the side surface 3130 of the device that is not parallel to the junction surface of these two layers, which is the active layer. A second conductivity type electrode 311 is formed on the upper second conductivity type layer 39 of this light receiving element 313, and a first conductivity type electrode 37 is formed on the back surface 1 of the first conductivity type substrate 36 corresponding to this. It is formed.

In the printer light source having such a structure, light emitted from the side surface opposite to the light emitting end surface 3120 of the light emitting diode enters the light receiving element T-313 via the first separation groove 48-1. Second conductivity type electrode 311 and first conductivity type electrode 3 of any light receiving element
By applying a predetermined reverse voltage during 7, a monitor signal of the light output of each light emitting diode that is incident on the light receiving element at an arbitrary position in the printer light source using light emitting diodes is output. I can do ().

Since this monitor changes in response to the magnitude and increase/decrease of the light output to each light emitting diode, the current injected into the light emitting diode is electrically controlled based on the monitor signal from the light receiving element. (Thus, the light output of each light emitting diode in the light emitting diode array can be made uniform with high precision, and changes in the light output over time can be suppressed.

By using the integrated light emitting diode array of this embodiment as a printer light source, an optical printer capable of high-density, highly uniform, and high-quality printing can be realized.

Note that the side-illuminated light receiving element 313 shown in this embodiment has a laminated structure of a first conductivity type WJ 310 and a second conductivity type layer 39, but this laminated structure is not particularly limited. A light receiving element having any laminated structure can be used as long as it is a side-illuminated light receiving element.

Further, the number of light emitting diodes that input light into each light receiving element is not particularly limited.

Embodiment 2 (See FIGS. 3 and 4) FIG. 3 shows a printer light source using a multilayer light emitting diode array according to the present invention, viewed diagonally from above on its light emitting end surface. FIG. 4 shows a longitudinal section of the light source in the light emission direction. The light emitting section of this printer light source is composed of an edge-emitting type light emitting diode 410. This edge-emitting type light emitting diode is made of a plurality of layers including a first conductivity type thalassod layer 45, an active layer 44 which is a light emitting layer, a second conductivity type cladding layer 43, and a camp layer 42 on a first conductivity type substrate 46. It is formed of a laminated structure (double heterostructure). A second separation groove 1I8-2 is formed perpendicularly to the substrate surface of the first conductivity type substrate 4G from the surface of this laminated structure, that is, the upper surface of the cap layer, and reaches the substrate, and this separation groove allows the light emitting diode to -l Each light emitting diode in the hair array is electrically isolated. Further, the light emitting end face of each light emitting diode array is formed perpendicular to the substrate surface.

Further, the can layer 42 of each of these light emitting diodes
A second conductivity type electrode 41 is formed on the top, and a first conductivity type electrode 47 is formed on the back surface of the first conductivity type substrate 46.
is formed.

In this configuration, by flowing a predetermined forward current between an arbitrary second conductivity type electrode 41 and the first conductivity type electrode 47, light output 412 is generated from the light emitting diode at a desired position in the light emitting diode array. can be obtained.

On the same substrate on the side opposite to the light emitting end surface 4100 of the light emitting diode array, each light emitting diode in the light emitting diode array is electrically and spatially separated by a first separation groove 48-1, and the light of each light emitting diode is separated. A side-illuminated light receiving element 411 for monitoring output is integrated adjacent to each light emitting diode.

This light-receiving element is composed of a laminated structure (double heterostructure) whose material composition, laminated structure, etc. are exactly the same as that of the light emitting diode which is the light emitting part, and emits light from the side surface 4110 of the element which is not parallel to the surface of the active layer. Light from the diode is incident. On the cap layer 42 of this light-receiving element,
A second conductivity type electrode 49 is formed, and a first conductivity type electrode 47 is formed on the back surface of the first conductivity type substrate 46. Further, the light receiving element is formed so that light from a plurality of light emitting diodes is incident on one element.

In the printer light source having such a structure, light emitted from the opposite side of the light emitting end face 4100 of one light emitting diode enters the light receiving cable 411 via the first separation groove 48-1. By applying a predetermined reverse voltage between the second conductivity type electrode 49 and the first conductivity type electrode 47 of an arbitrary light receiving element, the light receiving element at an arbitrary position within the printer light source using a light emitting diode can A monitor signal of the light output of each light emitting diode that is incident on the light receiving element can be obtained.

Furthermore, by moving each light emitting diode corresponding to each light receiving element in time and minutes, it becomes possible to monitor the light output of the operating light emitting diode. This monitor signal changes depending on the magnitude and increase/decrease of the light output of the light emitting diode, so by electrically controlling the current injected into the light emitting diode based on the monitor signal from the light receiving element, the light emitting diode The light output of each light emitting diode I in the array can be made uniform with high precision, and changes in the light output over time can be suppressed.

Furthermore, as shown in this example, when the light receiving element is formed so that light from a plurality of light emitting diodes is incident on one light receiving element, the number of light receiving elements is substantially larger than the number of light emitting diodes. This makes it possible to reduce the number of people to one person, and it becomes possible to suppress a significant increase in the wiring density for elements, which is a big problem when forming a high-density printer light source.

As described above, by using an integrated light emitting diode array having the structure shown in this example as a printer light source, it is possible to easily realize an optical printer that is capable of high-density, high-uniform, and high-quality printing. I can do it.

Embodiment 3 (See FIGS. 5 and 6) FIG. 5 shows a printer light source using a monolithic light emitting diode according to the present invention, viewed diagonally from above on its light emitting end surface. FIG. 6 shows a longitudinal section in the direction of the light emission axis.

The light emitting part of this printer light source is composed of an edge-emitting type light emitting diode 510, and this light emitting diode is arranged on a first conductivity type substrate 56 and a first conductivity type cladding R1.
J55, active layer 54 which is a light emitting layer. A laminated structure (
double heterostructure). A second separation groove 58 that extends from the surface of this laminated structure, that is, the upper surface of the cap layer 52 and reaches the first conductivity type substrate perpendicularly to the substrate surface.
-2 is formed, and each light emitting diode in the light emitting diode array is electrically isolated by this second separation groove 58-2. Further, the light emitting end face of each light emitting diode array is formed perpendicular to the substrate surface.

Furthermore, a cap 1552 of each of these light emitting diodes
A second conductivity type electrode 51 is formed on the top, and a first conductivity type electrode 51 is formed on the back surface of the first conductivity type substrate 56.
7 is formed.

In such a configuration, any second conductivity type electrode 51 and the first
By flowing a predetermined forward current between the conductivity type electrodes 57, light output 512 can be obtained from the light emitting diodes at any arbitrary position within the light emitting diode array.

On the same substrate on the side opposite to the light emitting surface 5100 of the light emitting diode array, each light emitting diode in the light emitting diode is electrically and spatially separated by a first separation groove 58-1, and the light output of each light emitting diode is separated. A side-illuminated light receiving element 511 for monitoring the light emitting diode is integrally formed in momentary contact with each light emitting diode. This light-receiving element is composed of a laminated structure (double heterostructure) in which the material composition, laminated structure, etc. are exactly the same as that of the light emitting diode which is the light emitting part, and the light is emitted from the side surface 5110 of the element which is not parallel to the surface of the active layer. Light from the diode is incident.

On the cap M52 of this light receiving element, a second
A conductivity type electrode 59 is formed, and a first conductivity type substrate 56
A first conductivity type electrode 57 is formed on the back surface of the substrate. Furthermore, this light-receiving element is formed so that only the light from one light-emitting diode element is incident on one light-receiving element.

In the printer light source having such a structure, light emitted from the side surface opposite to the light emitting end surface 5100 of the light emitting diode enters the light receiving element 511 via the first separation groove 58-1. By applying a predetermined reverse voltage between the second conductivity type electrode 59 and the first conductivity type electrode 57 of an arbitrary light receiving element, the light receiving element at an arbitrary position within the printer light source using a light emitting diode can A monitor signal of the light output of each light emitting diode incident on the light receiving element is obtained.

This monitor signal changes depending on the magnitude and increase/decrease of the light output of the light emitting diode, so the current injected into the light emitting diode is electrically controlled based on the monitor signal from the light receiving element.

The light output of each light emitting diode in the light emitting diode array can be made uniform with high precision, and changes over time in the light output can be suppressed.

Furthermore, as shown in this embodiment, when the light receiving element is formed so that only the light from one light emitting diode element is incident on one element, there is no need to time-divisionally drive the light emitting diode, and the light emitting Since all the light emitting diodes in the diode array can be driven simultaneously, it is also possible to significantly increase printing speed.

As described above, by using an integrated light emitting diode array having a structure as shown in each embodiment as a printer light source, an optical printer capable of high-density, highly uniform, high-quality, and high-speed printing can be realized.

The light-emitting materials used to form the printer light source using an integrated light-emitting diode array as shown in each of the above examples include GaAs, Al, which is a m-v group compound semiconductor.
GaAs, AIGaInP, InP.

InGaAsP, InGaP, InAIP, GaAsP
.

GaN, InAs, InAsP, InAsSb, etc., or Zn5e, ZnS which is a 1l-VI group compound semiconductor
.

ZnSSe, CdS, CdSe, Cd5Se, CdTe
.

HgCdTe, etc., and rV-VI group compound semiconductors Pb5e, PbTe, Pb5nSc, Pb5nTe, etc.
etc., and it is possible to utilize the advantages of each material and apply it to the structure of the present invention.

For example, in a printer light source using an integrated light emitting diode array shown in Embodiment 1 of the present invention, the stacked structure of the edge-emitting light emitting diode, which is the light emitting part, uses an n-GaAs substrate as the first conductivity type substrate 36. , is realized by using a double heterostructure consisting of n-AlGaAs for the first conductivity type clad WJ35, GaAs for the active layer 34, p-AlGaAs for the second conductivity type clad WJ33, and p-GaAs for the cap layer 32. Ru. At this time, the material for the active layer 34 is selected depending on the emission wavelength of the optical output, and a material whose energy gap is larger than that of the active layer is selected for the Cranot layer.

In addition, since the laminated structure of the side-illuminated light receiving element 313 only needs to absorb the incident light from the light emitting diode, the first
Conductivity type layer 3 ] 0 is n-GaAs, second conductivity type layer 39 is p
- Realized by using GaAs. At this time, the side-illuminated laminated structure and its material are not particularly limited, and a side-illuminated structure and material that absorbs incident light from the light emitting diode and generates a monitor current are selected.

The same applies to the printer light source using the integrated light emitting diode array shown in Example 2 and Example 3, and the laminated structure thereof is, for example, an n-GaAs substrate on the first conductivity type substrate 46, 56. The first conductivity type cladding layer 45.55 is made of n-AlGaAs and the active layer 144.
54, GaAs, second conductivity type cladding layer 43.5
3 is p-AlGaAs, cap layer 42.52 is p-G.
This is realized by using a double heterostructure consisting of aAs1.

As in the case of Example 1, the material for the active layer is selected depending on the emission wavelength of the optical output, and the material for the cladding layer is selected from a material whose energy gap is larger than that of the active layer.

Furthermore, the laminated structure used in the edge-emitting light emitting diode, which is the light emitting part of the printer light source using the integrated light emitting diode array, as shown in each of the above embodiments, is as follows:
In addition to the double heterostructure as described above, a single heterostructure, a homozygous structure, etc. are also used.

In the printer light source using the integrated light emitting diode array shown in each of the above embodiments, the light emitting end faces 3120, 4100.5 of the edge emitting type light emitting diode, which is the light emitting part,
100 is formed perpendicular to the first conductivity type substrate surface, but its light emitting end surface does not necessarily have to be perpendicular to the substrate surface, and may be substantially perpendicular or not parallel to the active layer. Any surface that effectively functions as a light emitting end surface can be used.

In addition, in the printer light source using the integrated light emitting diode array shown in each of the above embodiments, the side-illuminated light receiving elements 313, 411, and 511 for monitoring the light output of each light emitting diode in the light emitting diode array are the first The light emitting diode is connected through the separation groove 38-1.48-1.58-1.
The substrate surface of each light emitting diode and the light receiving element that monitors its light output is integrated and formed adjacent to the light emitting surface of each light emitting diode 1 on the same substrate as the 1-array. The above positional relationship is not limited to the positional relationship shown in each of the above embodiments, and the edge-emitting type light emitting diode array and side-illuminated light receiving element
If the light emitting diodes are integrated on the same substrate via lζ and can function as shown in each example,
Each of the light emitting diodes and the light receiving element in the array 1 to 1 may be in any positional relationship on the same substrate.

Furthermore, in each of the above embodiments, the separation grooves formed between the light emitting diodes 1 in each light emitting diode 1 array and the separation grooves formed between the light emitting diodes and the light receiving elements have a product f.
Although it is formed to reach the first conductivity type substrate from the surface of the rj structure, essentially it is sufficient to electrically isolate the active layers of adjacent light emitting diodes and the active layers of the light emitting diode and the light receiving element. Therefore, the bottom does not necessarily have to reach the first conductivity type substrate 36, 46, 56,
Passing through active layer 3/I, 44.54, first conductivity type crat R135, 45, 55 (or first conductivity type layer 310)
It is fully functional if it reaches .

Further, the second dividing groove formed between each light emitting diode in the light emitting diode array and the first dividing groove formed between the light emitting diode and the light receiving element are not necessarily of the same shape or the same shape.
It doesn't have to be deep.

Such a portion H'tR is normally formed by a method such as etching, but due to the function of the printer light source of the present invention, it is possible to form a narrow separation groove with a side surface perpendicular to the substrate surface with high precision. From this viewpoint, it is desirable to use a highly anisotropic dry etching method or the like.

As described above, in the present invention, in order to realize high-density, high-quality printing, one light emitting diode array is used, for example, six
It is composed of an edge-emitting type light emitting diode array that can form a light emitting part with a zero density such as 00dρi or more, and a side-illuminated type light receiving element that is easy to integrate on the same substrate.
The light emitting diode array is electrically and spatially separated from the light emitting diode array by a separation groove, and is monolithically integrated, so that the light output of each light emitting diode in the light emitting diode array can be monitored.

Based on the monitor signal from this light receiving element.

By correcting and controlling the light output of each light emitting diode in a light emitting diode array, conventionally within the same chip
0%, and the variation in the light output of each light emitting diode in a light emitting diode array, which was up to ±50% between chips, has been made uniform with extremely high precision to less than ±5%.
Changes in optical output over time can be suppressed.

Thus, by using the integrated light emitting diode array according to the present invention as a printer light source, e.g.
A high-density optical printer light source using a single light-emitting diode array has been realized, which is capable of high-quality printing at a high density of 0 dpi or more and with high uniformity in print dot size and print density.

(Actions and Effects of the Invention) (1) Effects and Effects on Claim 1 The invention shown in claim 1 provides a light-emitting diode array with a light emitting diode array, for example, 600
It consists of an edge-emitting type light emitting diode array that can form a light emitting part at a high density of dpi or more, and furthermore, on the same substrate, a side-illuminated type light receiving element, which is easy to integrate due to its structure, is installed with a one-separation groove to reduce electrical and spatial issues. The light emitting diode array is separated from the light emitting diode array and integrated seven times, making it possible to monitor the light output of each light emitting diode in the light emitting diode array. By correcting and controlling the light output of each light emitting diode in the light emitting diode array based on the monitor signal from this light receiving element, it can reach up to ±40% within the same chip and up to ±50% between chips. It has now become possible to equalize the variations in light output of each light emitting diode in a light emitting diode array with extremely high accuracy of ±5% or less, and to suppress changes in light output over time. By this, for example, 600dpi
It has now become possible to realize an optical printer that is capable of high-density, uniform, and high-quality printing.

(2) Effects and effects on claim 2 The invention shown in claim 2 is such that, in order to realize high-density and high-quality printing, one light-emitting diode array is used, for example, 60
Purchase an edge-emitting type light emitting diode array that can form a light emitting part at a high density of 0 dpi or more, and then add a side-illuminated type light receiving element that is structurally easy to integrate on the same substrate.
The light emitting diode array is electrically and spatially separated from the light emitting diode array by l'I:G and monolithically integrated, so that the light output of each light emitting diode in the light emitting diode array can be monitored. Based on the monitor signal from this light-receiving element, it is now possible to correct and control the previous output of each light-emitting diode in the light-emitting diode array.
The variation in light output of each light emitting diode in a light emitting diode array, which used to reach ±50%, can now be made uniform with extremely high precision to less than ±5%, and changes in light output over time can be suppressed. Became. Furthermore, by making the edge-emitting type light emitting diode-1- and the side-illuminated type light receiving element have exactly the same material composition and laminated structure, it has become possible to greatly simplify the manufacturing process. . As a result, it has become possible to realize an optical printer that is capable of high-density, highly uniform, and high-quality printing of, for example, 60 (Mpi) or more.

(3)=i''1 Operation and effect for claim 3 17 The invention shown in claim 3 is to increase the density of one light emitting diode array to, for example, 600 dpi or more in order to achieve high density and high quality printing. It consists of an edge-emitting light emitting diode array that can form a light emitting part, and a side-illuminated light receiving element, which is structurally easy to integrate, is mounted on the same substrate by a separation groove.
j. The light emitting diode is monolithically integrated separately from the spatial diode array so that the light output of each light emitting diode in the one light emitting diode array can be monitored. Based on the monitor signal from this light-receiving element, it has become possible to correct and control the light output of each light-emitting diode in the light-emitting diode array. Furthermore, by configuring the light emitting diode 1 and the light receiving element with a laminated structure having exactly the same material composition and laminated structure, it has become possible to greatly simplify the manufacturing process.

Furthermore, since the structure is such that light from multiple light-emitting diodes is incident on one light-receiving element, it is possible to substantially reduce the number of light-receiving elements than the number of light-emitting diodes, resulting in high density This makes it possible to suppress the large increase in wiring density for elements, which is a major problem when forming printer light sources. Time-divisionally driving each light emitting diode in the integrated light emitting diode array according to the present invention;
By correcting and controlling the light output of each light-emitting diode based on the monitor signal from the light-receiving element, the light output within the light-emitting diode array can be reduced, which previously reached ~±40% within the same chip and ~±50% between chips. It has become possible to uniformize the variation in the light output of each light emitting diode with extremely high accuracy of ±5% or less, and to suppress changes in the light output over time. As described above, by using the integrated light emitting diode array according to the present invention as a printer light source, it is possible to extremely easily realize an optical printer that is capable of high-density, highly uniform, and high-quality printing of, for example, 600 dpi or more. Became.

(4) Effects on Claim 4 The invention shown in Claim 4 is such that in order to realize high-density and high-quality printing, one light emitting diode array, for example, 600
It consists of an edge-emitting type light emitting diode array that can form a light emitting part at a high density of dpi or more, and furthermore, on the same substrate, a side-illuminated type light receiving element, which is structurally easy to integrate, is electrically and spatially separated by a separation groove. It is monolithically integrated separately from the light emitting diode array, so that the light output of each light emitting diode in the light emitting diode array can be monitored. Based on the monitor signal from this light-receiving element, it has become possible to correct and control the light output of each light-emitting diode in the light-emitting diode array. Also,
By configuring the light-emitting diode and the light-receiving element with a laminated structure having exactly the same material composition and laminated structure, it has become possible to greatly simplify the manufacturing process. Furthermore, since the configuration is such that only the light from one light emitting diode in the light emitting diode array is incident on one light receiving element, the light emitting diodes can be activated at any time without time-division activation of each light emitting diode. It is now possible to obtain a monitor signal for the light output of a light emitting diode from a light receiving element in a light source of a printer using a light emitting diode. By correcting and controlling the light output of each light emitting diode in the integrated light emitting diode array according to the present invention based on the monitor signal from the light receiving element, it is possible to improve the optical output by ~±40% within the same chip and ~±50% between chips. It has now become possible to uniformize the variation in the light output of each light emitting diode in a light emitting diode array with an extremely high precision of less than ±5%, and to suppress changes in light output over time. Furthermore, because the structure allows the monitor signal of the light output of each light emitting diode to be obtained from the corresponding light receiving element at any time without time-sharing the light emitting diodes, it is possible to operate all the light emitting diodes at the same time. This has also made it possible to significantly increase printing speed. Thus, by using the integrated light emitting diode array according to the present invention as a printer light source, e.g.
It has become possible to realize an optical printer that is capable of high-density, uniform, and high-quality printing of pi or higher.

[Brief explanation of drawings]

1, 3, and 5 are perspective views of a high-density optical printer light source according to the present invention, FIG. 2 is a sectional view of FIG. 1, FIG. 4 is a sectional view of FIG. 3, and FIG. FIG. 6 is a sectional view of FIG. 5, and FIGS. 7 and 8 are explanatory views of the prior art. 38-1.48-1.58-1...first separation groove, 31
2.410°510... Edge-emitting diode, 31
3.411.511...Side-illuminated light receiving element, 312
0.4100.5100--Light-emitting end surface of light-emitting group, 3130.411.0.5110--Light-incidence side surface of light-receiving element. (Other names) RuZe, :g-f Chiδ Power 4 illusion η-Iv) O Reiichi G remainder

Claims (1)

[Claims] 1. A light-emitting diode array including a plurality of light-emitting diodes arranged in at least one row, and when each light-emitting diode is placed facing a photoconductor and is selectively turned on, the light emitting diode is arranged on the photoconductor. In the printer light source capable of forming a dot-divided image, the light-emitting diode array is constituted by edge-emitting light-emitting diodes in which light output is obtained from a side surface of the element that is not parallel to the plane containing one active layer of each light-emitting diode, and A side-illuminated light-receiving element that is electrically and spatially separated from the edge-emitting diode array by a first separation groove and receives light from a side surface of the element that is not parallel to the surface containing the active layer is the same as the edge-emitting light-emitting diode. An integrated light emitting diode array is configured by monolithically integrating the light emitting diode on a substrate, and the light from the edge emitting type light emitting diode is made incident on the side incident type light receiving element, thereby responding to the magnitude of the light output of the edge emitting type light emitting diode. A high-density optical printer light source characterized in that a monitor signal for controlling the light output of each light-emitting diode of the edge-emitting type light-emitting diode is obtained from the side-illuminated light receiving element. 2. The high-density optical printer light source according to claim 1, wherein the edge-emitting type light emitting diode and the side-illuminated type light receiving element are constructed of the same laminated structure. 3. The high-density optical printer light source according to claim 2, wherein the side-illuminated light-receiving element is configured such that light from a plurality of the edge-emitting light-emitting diodes is incident on each light-receiving element. 4. In claim 2, the side-illuminated light-receiving element and the edge-emitting type light-emitting diode are formed in one-to-one correspondence, and for each light-receiving element of the side-illuminated type light-receiving element, the edge-emitting type light emitting diode is formed in a one-to-one correspondence. A high-density printer light source characterized by being configured so that only light from one light emitting diode element in a diode array is incident.