JP2001228417A - Light source unit, image forming device using light source unit, and production method of light source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source unit using an inexpensive adjusting device which can perform adjustment for arranging the beam spot of a plurality of laser beams in the prescribed direction on a recording medium in advance, and which can enhance the degree of freedom of designs of a scanning optical system using it and itself. SOLUTION: The light source unit 19 is equipped with a multi-beam laser diode 36 to which a plurality of light emitting points are located on the design on a virtual straight line decided by a notch formed at a stem 49, and a collimator lens 38 which converts the laser beam emitted from each light emitting point into the parallel luminous flux. When the light source unit 19 is installed in the scanning optical system, light is emitted based on position data corresponding to the deviation from the virtual straight line of each light emitting point previously stored as scanning on a recording medium, arranging the beam spot of a plurality of laser beams which pass the collimator lens 38 in the prescribed direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source unit used in a scanning optical system, an image forming apparatus using the light source unit, and a method for producing the light source unit.

[0002]

2. Description of the Related Art As an image forming apparatus such as a digital copying machine or a laser printer, there is known an image forming apparatus in which a laser type is mounted on a scanning optical system. Further, as a light source used in such a laser-type scanning optical system, a light source using a multi-beam laser diode is becoming mainstream in order to meet demands for higher writing accuracy and higher speed.

FIG. 22 schematically shows a laser scanning optical system, 1 is a light source unit, 2 is a polygon mirror, and 3 is f.
The θ lens 4 is a photoconductor. The light source unit 1 includes a multi-beam laser diode 5 and a collimator lens 6, and the multi-beam laser diode 5 has a light emitting point 7a.
7d (see FIG. 24) to emit a laser beam P. This laser beam P is converted into a parallel light beam by the collimator lens 6 and reflected on the rotating polygon mirror 2 so that the surface 4a of the photoconductor 4 is scanned in the main scanning direction Q _1.
Scan.

As shown in FIG. 23, laser beams P from two adjacent light emitting points have a predetermined pitch X ₁ in a sub-scanning direction Q ₂ orthogonal to the main scanning direction Q ₁ on the surface 4 a of the photoreceptor 4. And a beam spot 8 is formed. here,
The multi-beam laser diode 5 has four emission points 7a
-7d, the four laser beams P simultaneously scan the surface 4a of the photoconductor 4 to write image information.

[0005] The multi-beam laser diode 5
As shown in FIG. 24, a laser diode chip 9 having a rectangular parallelepiped shape, a pedestal 10 to which the laser diode chip 9 is adhered, and a stem 11 are provided. Stem 11
A pair of notches 12, 12 of the V-shape is formed when viewed from the front, the light emitting point 7a~7d is sharpened tip 12a of the notch 12, 12, designed on the virtual straight line L ₁ obtained by connecting 12a It is provided on the front surface 13 of the laser diode chip 9 so as to be located above. Therefore, the light emitting points 7a to 7a
the extending direction of the straight line connecting the d to approximately (hereinafter. referred to as "arrangement direction") Given Q _3, the arrangement direction Q ₃ are but in theory should match with the direction of extension of the imaginary straight line L _1,
Actually a common that the light emitting point 7a~7d by errors of manufacturing a multi-beam laser diode 5 is shifted from on the virtual straight line L _1, the arrangement direction Q ₃ as shown exaggeratedly in FIG. 25 have a slight inclination θ ₁ with respect to the virtual straight line L _1.

Conventionally, this type of multi-beam laser diode 5 has a light emitting point 7 due to manufacturing technology.
It is difficult to narrow the interval between a to 7d, and the light emitting points 7a to 7d
The arrangement direction Q ₃ of 7d than the projection of the laser beam P on the photosensitive member 4 in a state to match the sub-scanning direction Q ₂ becomes coarse pitch X ₁ in the sub-scanning direction Q _2, to obtain the desired image quality could not. Then, for example, Japanese Patent Laid-Open No. 57-8887
JP, as described in JP-A-9-96771, inclined so as to be oblique to the arrangement direction Q ₃ of the light emitting points 7a~7d in the sub-scanning direction Q _2, the pitch X ₁ narrow the sub-scanning direction Q ₂ of the writing density achieving reduction (recording density) has been to improve (JP 57-8887 JP Figure 1, see FIG. 3 JP 9-96771).

[0007]

However, in the configuration described in Japanese Patent Application Laid-Open No. 57-8887, the photosensitive member 4
For each beam spot 8 above is adjusted to be aligned in the sub-scanning direction Q _2, time lag of the laser beam P from the light emitting points 7a~7d while rotating the polygon mirror 2 (the light emitting points 7a laser beam P from ~7d must detect a deviation) of time to reach a predetermined position in the main scanning direction Q _1. Since the time lag of each laser beam P usually needs to be detected on the order of ns (nanosecond), a jig for the adjustment (hereinafter, “adjustment device”)
That. ) Requires an oscilloscope or the like, and there is a problem that the adjustment device becomes expensive.

Further, the light source unit 1 including the semiconductor laser is a consumable item and is a replacement part in the market for a copying machine or a laser printer. However, in the configuration described in the publication, the light source unit 1 is separated from the scanning optical system. Since the adjustment cannot be performed in the state, when the light source unit 1 is replaced, an expensive adjustment device as described above is brought to the market and only the light source unit 1 is replaced and then the adjustment is performed. It is necessary to replace the entire scanning optical system including the mirror 2 and the like. Therefore, it takes time and cost to replace the light source unit, which also hinders the serviceability to the user.

On the other hand, according to the configuration described in Japanese Patent Application Laid-Open No. 9-96871, it is necessary to detect the laser beam P while the polygon mirror 2 is rotated. However, there is a problem that the dimensional relationship is limited because the laser beam P is detected by one sensor, and the versatility is lacking. In particular, in today spacing of the light emitting point 7a~7d is the development of dense multi-beam laser diode 5 is progressing, multi the arrangement direction Q ₃ of the light emitting points 7a~7d in a state to match the sub-scanning direction Q ₂ It is possible to dispose the beam laser diode 5, but in such a case, the configuration described in the publication cannot identify and detect a plurality of laser beams P and cannot perform the above adjustment. Occurs.

The present invention has been made in view of the above circumstances, and it is possible to perform adjustment for arranging the beam spots of a plurality of laser beams in a predetermined direction on a recording medium in advance using an inexpensive adjustment device. And a light source unit capable of increasing the degree of freedom in designing a scanning optical system using the light source unit itself, an image forming apparatus using the light source unit, and a method for producing the light source unit. Is an issue.

[0011]

In order to solve the above-mentioned problems, a light source unit according to the first aspect of the present invention is a multi-purpose light source unit in which a plurality of light emitting points are located on a virtual straight line defined by a notch formed in a stem. A beam laser diode, a light source unit provided in a scanning optical system with an optical lens that converts a plurality of laser beams emitted from each of the light emitting points into a parallel light beam, wherein the multi-beam laser diode and the optical lens are A deviation from the virtual straight line of each of the light emitting points stored in advance so that a beam spot of a plurality of laser beams transmitted through the optical lens is arranged in a predetermined direction and scans on a recording medium when installed in a scanning optical system. The gist is to emit light based on the position data corresponding to.

According to the first aspect of the present invention, each light emitting point emits light based on the position data corresponding to the deviation of each light emitting point from the virtual straight line. Since it is cheaper than an adjustment device for detecting a time lag and its position data is stored in advance, adjustment for arranging a beam spot in a predetermined direction on a recording medium is performed in advance (market). Before shipping to)
It can be carried out. In addition, since light emission is performed based on the data stored in advance in this manner, the design of the scanning optical system using the light source unit or the light source unit itself does not limit the light emission timing, and the design flexibility is increased. be able to.

The light source unit according to claim 2, further comprising storage means for preliminarily storing the position data or light emission timing data corresponding to the light emission timing of each of the light emitting points calculated based on the position data. The gist of the invention is to control the light emission at each of the light emitting points based on any of the data stored in.

According to a third aspect of the present invention, there is provided a light source unit including control means for controlling light emission at each of the light emitting points based on any data stored in the storage means.

According to a fourth aspect of the present invention, there is provided a light source unit including a bar code label obtained by converting any one of the position data and the light emission timing data into a bar code.

According to a fifth aspect of the present invention, in the light source unit, the bar code label includes numerical data obtained by digitizing either the position data or the light emission timing data.

According to the light source unit of the present invention, the storage means in which the position data or the light emission timing data corresponding to the light emission timing calculated based on the position data are stored in advance by the light source unit Since the unit itself is provided, it is possible to replace only the light source unit without making adjustments to align the beam spot in a predetermined direction on the recording medium in the market, greatly reducing the labor and cost required for replacing the multi-beam laser diode. Can be reduced.

According to a sixth aspect of the invention, an image forming apparatus includes the light source unit according to any one of the first to fifth aspects.

According to a seventh aspect of the present invention, there is provided an image forming apparatus including the light source unit according to the first aspect, and the light emission timing corresponding to the position data or the light emission timing of each of the light emission points calculated based on the position data. A storage unit storing data in advance is provided separately from the light source unit,
The gist of the invention is to control the light emission at each of the light emitting points based on any data stored in the storage means.

An image forming apparatus according to an eighth aspect of the present invention includes the light source unit according to the first aspect, and further includes a light emission timing corresponding to the position data or a light emission timing of each of the light emission points calculated based on the position data. A storage unit storing data in advance is provided separately from the light source unit,
The gist is that control means for controlling light emission at each of the light emitting points based on any data stored in the storage means is provided integrally with the light source unit.

According to a ninth aspect of the present invention, there is provided an image forming apparatus including the light source unit according to the first aspect, and the light emission timing corresponding to the position data or the light emission timing of each of the light emission points calculated based on the position data. The gist of the present invention is to provide a storage unit that stores data in advance and a control unit that controls light emission at each of the light emitting points based on any data stored in the storage unit, separately from the light source unit.

According to a tenth aspect of the present invention, there is provided an image forming apparatus comprising the light source unit according to the second aspect, and controlling light emission of each of the light emitting points based on any data stored in the storage means. Is provided separately from the light source unit.

In the image forming apparatus according to the present invention, a bar code label having a bar code symbol obtained by converting any one of the position data and the light emission timing data into a bar code is integrated with the light source unit or separately. The point is to prepare.

According to a twelfth aspect of the present invention, in the image forming apparatus, the bar code label includes numerical data obtained by digitizing either the position data or the light emission timing data. .

An image forming apparatus according to a thirteenth aspect is characterized in that the image forming apparatus further comprises an input means for reading the bar code symbol by a reading device and inputting a result of reading by the reading device to the storage means. .

According to a fourteenth aspect of the present invention, there is provided an image forming apparatus comprising an input unit for inputting the numerical data to the storage unit.

[0027] According to a fifteenth aspect of the present invention, the input means is a telecommunication line.

[0028] The image forming apparatus according to a sixteenth aspect is characterized in that the input means is a ten-key provided on a main body of the image forming apparatus.

An image forming apparatus according to a seventeenth aspect is characterized in that the light source unit is detachable.

According to the image forming apparatus of the present invention, the effects of any one of the first to fifth aspects can be enjoyed in the image forming apparatus.

In the method for producing a light source unit according to the present invention, a plurality of light-emitting points are designed on a virtual straight line defined by a notch formed in a stem, and the light-emitting unit emits light from each of the light-emitting points. An optical lens that converts a plurality of laser beams into a parallel light beam, wherein the multi-beam laser diode emits light in accordance with an output signal of a control means, and wherein the plurality of laser beams are transmitted through the optical lens. A position data obtaining step of projecting the laser beam onto a light receiving element to obtain position data corresponding to a deviation of each of the light emitting points from the virtual straight line, and storing the position data obtained in the position data obtaining step in storage means. And a storage step of causing

According to a nineteenth aspect of the present invention, there is provided a light source unit producing method, wherein a plurality of light emitting points are designed on a virtual straight line defined by a notch formed in a stem, and the light emitting points emit light from the light emitting points. An optical lens that converts a plurality of laser beams into a parallel light beam, wherein the multi-beam laser diode emits light in accordance with an output signal of a control means, and wherein the plurality of laser beams are transmitted through the optical lens. A position data obtaining step of projecting the laser beam onto a light receiving element to obtain position data corresponding to a deviation of each of the light emitting points from the virtual straight line, and the optical lens when the light source unit is installed in a scanning optical system. The position is such that the beam spots of a plurality of laser beams transmitting through the recording medium are scanned while being aligned in a predetermined direction. A light emission timing data calculating step of calculating light emission timing data relating to a light emission timing of each of the light emission points based on data, and a storage step of storing the light emission timing data obtained in the light emission timing data calculation step in a storage unit. It is the gist to have.

The method of manufacturing a light source unit according to claim 20, wherein the bar having a bar code symbol corresponding to data obtained in either the position data obtaining step or the light emission timing data calculating step. A label creating step of creating a code label, an attaching step of attaching the barcode label to the light source unit or the image forming apparatus, and a reading step of reading the barcode symbol attached in the attaching step. The point is that the position data or the light emission timing data is stored in the storage means.

According to the method of manufacturing a light source unit of the present invention, it is possible to adjust the arrangement of the beam spots in a predetermined direction on the recording medium by coping with the deviation of each light emitting point from a virtual straight line. Since the position data to be obtained is obtained, the adjusting device is inexpensive as compared with the case of detecting the time shift of the ns order, and the data on the light emission timing calculated based on the position data is stored in the storage means. The adjustment can be completed in advance (before the light source unit is shipped to the market). Further, since the light emission of the manufactured light source unit is performed based on the data stored in advance in this way, whether the scanning optical system in which the light source unit is used or the design of the light source unit itself limits the light emission timing. And the degree of freedom of design can be increased.

[0035]

Embodiments of the present invention will be described with reference to the drawings.

[Structure of Light Source Unit] FIG. 1 is an exploded perspective view of a light source unit 19 according to the present invention. In FIG. 1, reference numeral 20 denotes a mounting bracket. The mounting bracket 20 includes a bottom wall 21, an upright wall 22, a side wall 23,
23.

A pair of positioning holes 21a,
21a and through holes 21b, 21b are formed.
As shown in FIG. 2, positioning reference portions 24 are formed on the bottom surface of the bottom wall portion 21. Positioning reference part 24
Is abutted against a positioning reference portion formed on the housing 60 described later.

The upright wall portion 22 is provided with a circular through hole 25. As shown in FIGS. 3 and 4, a pair of positioning reference portions 26, 26 are provided on both sides of the circular through hole 25 on the back surface of the upright wall portion 22. Reference surface (reference surface defining sub-scanning direction) 26a of positioning reference portion 26
Are formed substantially perpendicular to a reference plane (reference plane defining the main scanning direction) 24a of the positioning reference section 24. The pair of positioning reference portions 26, 26 are provided with screw insertion holes 27, 27, respectively.

On the back surface of the upright wall portion 22, a circular fitting tube 28 and board mounting portions 29 and 30 are further provided. The circular fitting cylinder 28 is formed concentrically with the circular through-hole 25, and has an inner diameter equal to the diameter of the circular through-hole 25. A pin 31 protrudes between the circular fitting cylinder 28 and one positioning reference portion 26. A circuit board 32 is mounted on the board mounting portions 29 and 30. The circuit board 32 has a CPU 33 as control means and an EEP as storage means.
A ROM 34 is provided.

A base member 35 shown in an enlarged manner in FIG. Base member 3
5 holds the multi-beam laser diode 36 and has a circular fitting cylinder 37 on the front. The outer diameter of the circular fitting cylinder 37 is formed to be slightly smaller than the inner diameter of the circular fitting cylinder 28, and is fitted into the circular fitting cylinder 28.

The collimating lens 3 is provided in the circular fitting cylinder 37.
8 are formed. The collimator lens 38 is a multi-beam laser diode 3
It serves to convert the laser beam emitted from 6 into a parallel light beam.

The circular fitting cylinder 37 has an opening 40 at its center. The laser beam is emitted through the opening 40 toward the collimator lens 38. Circular fitting cylinder 37
Are formed with a pair of notches 37a, 37a sandwiching the opening 40, and the pair of notches 37a, 37a
One pair of engagement pieces 41a, 41a is engaged. The aperture member 41 has a slit 41b extending in the horizontal direction,
The laser beam passing therethrough is shaped.

On both sides of the front surface of the base member 35, positioning reference portions 42, 42 are formed at locations corresponding to the positioning reference portions 26, 26 of the mounting bracket 20. The pair of positioning reference portions 42, 42 are provided with screw holes 43, 43, respectively. Between the cylindrical fitting cylinder 37 and one of the positioning reference portions 42, an insertion hole 44 through which the pin 31 is inserted and which is used for roughly positioning the base member 35 is formed.

As shown in FIG. 6, on the rear side of the base member 35, a pressing plate mounting portion 46 for mounting the elastic pressing plate 45 is formed. The elastic pressing plate 45 has four pressing spring pieces 45a at the center thereof,
b and a pair of screw insertion holes 45c, 45c.

The pressing plate mounting portion 46 has a fitting hole 47 communicating with the opening 40. The cylindrical main body 48 of the multi-beam laser diode 36 is fitted into the fitting hole 47. Behind the fitting hole 47, a mounting reference hole 5 formed slightly larger in diameter than the stem 49 of the multi-beam laser diode 36 and serving as a mounting reference for the multi-beam laser diode 36 when the stem 49 is inserted.
0 is provided. The mounting reference hole 50 has its stem 4
9 has an abutment reference surface 51 against which the front surface 49a is abutted, and the depth of the mounting reference hole 50 is such that the back surface of the stem 49 abutted against the abutment reference surface 51 projects from the back surface of the pressing plate mounting portion 46. It is formed to the extent.

The pressing plate mounting portion 46 has screw holes 46a, 46a formed on both sides of the mounting reference hole 50 so as to overlap the screw insertion holes 45c, 45c of the elastic pressing plate 45. The elastic pressing plate 45 faces the back surface of the multi-beam laser diode 36 in a state where the multi-beam laser diode 36 is fitted to the base member 35, and biases and holds the multi-beam laser diode 36 by the pressing spring piece 45a. Screw holes 46a, 46a
Screws 52, 5 are inserted into the screw insertion holes 45c, 45c
2 is inserted and screwed to the base member 35.

FIGS. 7 and 8 show assembly drawings of the light source unit 19. The details of the assembly procedure will be described later.

[Configuration of Multi-beam Laser Diode] The multi-beam laser diode 36 has a pedestal 53 inside a cylindrical main body 48 as shown in an enlarged view in FIG.
Is provided. A rectangular parallelepiped laser diode chip 55 is attached to the attachment surface 54 of the pedestal 53. On a front surface 56 of the laser diode chip 55, four light emitting points 57a to 57d for emitting a laser beam are provided.

The stem 49 has a pair of V-shaped notches 58, 58 as viewed from the front. Each light emitting point 57a
~57d in the design defined by the notches 58, 58 (the notch 58 of the pointed part 58a, obtained by connecting 58a) but should be located on the virtual straight line L _2, in practice a multi the error of the manufacture of the beam laser diode 36, and virtual light emitting points 57a~57d linear L ₂
In general, there is a slight deviation between the two.

The engaging piece 4 of the elastic pressing plate 45 is attached to the stem 49.
A notch 59 engaging with 5b is provided at a position rotated by 90 ° from the notch 58 about the center of the cylindrical main body 48. When the multi-beam laser diode 36 is attached to the base member 35, the notch 59 and the engagement piece 45b engage to position the multi-beam laser diode 36 with respect to the base member 35.

[Structure of Scanning Optical System] FIGS.
6 shows a housing 60 to which the light source unit 19 is detachably attached. The housing 60 is built in an image forming apparatus such as a copying machine or a laser printer. FIG. 10 shows a state before the light source unit 19 is mounted on the housing 60. FIG. 11 shows a state where the light source unit 19 is mounted on the housing 60. Is shown.

The housing 60 is provided with a polygon mirror 61 constituting a scanning optical system and an fθ lens 62. The housing 60 is provided with a positioning reference portion 63 in which the light source unit 19 is installed. The positioning reference portion 63 has a pair of positioning pins 64, 64 and a pair of screw holes 65, 65. Light source unit 19
Are the reference surfaces 24a, 2 of the positioning reference portions 24, 24.
4a is abutted against a reference surface 63a of the positioning reference portion 63, and positioning pins 64,
64 are inserted into the through holes 21b, 21b.
6 are fixed to the housing 60 by being inserted and screwed into the screw holes 65. By attaching the light source unit 19, the multi-beam laser diode 36 and the collimator lens 38 are inserted into the scanning optical system.

[0053] On one side wall of the housing 60, and an opening 67 is formed extending in the main scanning direction Q _1. When the multi-beam laser diode 36 is driven, each light emitting point 57
laser beam P emitted is scanned in the main scanning direction Q ₁ by the polygon mirror 61 to rotate from A～57d,
lens 62 and the aperture 67 and the photosensitive drum 68
Is irradiated on the photosensitive surface 68a. Each laser beam P
Write position of the photosensitive surface 68a, by being made emission control of the multi-beam laser diode 36 as described below, aligned in the sub-scanning direction Q _2.

[Production Method of Light Source Unit] (1) Assembling Step of Light Source Unit When assembling the light source unit 19, first, the base member 35 on which the multi-beam laser diode 36 is mounted is mounted on an optical characteristic adjusting device (not shown). A collimator lens 38 is attached to a chuck which is fixed and movable in three axial directions (three axial directions of X axis, Y axis and Z axis shown in FIG. 1 with respect to the fixed light source unit 19) of the optical characteristic adjusting device. Is gripped. Next, a light-curable adhesive (ultraviolet-curable adhesive) is applied to the lower surface of the collimator lens 38, and the multi-beam laser diode 36 is caused to emit light while the light-curable adhesive is positioned on the arc-shaped support portion 39.
The collimator lens 38 is moved so that the optical characteristics (parallelism and optical axis of each laser beam) of the four laser beams transmitted through 8 satisfy a predetermined standard. When the laser beam transmitted through the collimator lens 38 satisfies the desired optical characteristics, ultraviolet light is irradiated from above the transparent collimator lens 38 to cure the adhesive with the transmitted light flux, and the collimator lens 38 is moved to the arc-shaped support portion 39. Glue. Here, while four laser beams need to be adjusted in optical characteristics, only one collimator lens is moved, and adjustment cannot be performed independently for each of the four laser beams. After obtaining the optimum position of the collimator lens 38 with respect to
8 is adhered.

When the attachment of the collimator lens 38 is completed, the aperture member 41 is attached to the circular fitting cylinder 37 so as to cover the collimator lens 38. Then, the aperture member 41 and the circular fitting cylinder 37 are inserted through the circular through hole 25, and the pin 31 is inserted through the insertion hole 44, so that the reference surfaces 42a and 42a of the positioning reference portions 42 and 42 are formed.
42a is the reference surface 26a, 2 of the positioning reference portion 26, 26.
6a. In this state, the screw insertion holes 27, 27
, Screws 69, 69 with spring washers are inserted through them, and these are screwed into the screw holes 43, 43. Thereby, the multi-beam laser diode 36 is mounted on the mounting bracket 20 via the base member 35,
In this case the optical axis of the multi-beam laser diode 36 is parallel to the reference plane 24a of the positioning reference portion 24, the virtual straight line L ₂ is orthogonal to the reference plane 24a.

On the mounting bracket 20 to which the base member 35 is mounted, screws 70, 7 are attached to the substrate mounting portions 29, 30.
Then, the circuit board 32 is attached to the circuit board 32, and the terminals 71 of the multi-beam laser diode 36 are soldered to the circuit board 32.

(2) Position Data Acquisition Step Next, position data corresponding to the shift of each of the light emitting points 57 a to 57 d of the multi-beam laser diode 36 from the virtual straight line L _{2 is} defined as a unique one for each light source unit 19. Ask.

FIG. 12 schematically shows an adjusting device used for obtaining the position data. The adjusting device 72 includes a condenser lens (imaging lens) 73 and a CCD 7 serving as an image sensor.
4 and a reference mounting portion 75. Light source unit 19
Is set on the adjusting device 72 with the reference surface 24a of the positioning reference portion 24 abutting against the reference surface 75a of the reference mounting portion 75.

As shown in FIG. 13, the condenser lens 73
As the front focal distance f _1, the back focal length is formed to f ₁ '. The collimator lens 38 has a front focal length f _CO ′ and a rear focal length f _CO . The front focal position of the condenser lens 73 substantially coincides with the rear focal position of the collimator lens 38, and the imaging surface (area type image receiving surface) 74 a of the CCD 74 is located at the rear focal position of the condenser lens 73.

With the light source unit 19 set in the adjusting device 72, first, a drive voltage is simultaneously applied to each terminal 71 of the multi-beam laser diode 36.

As a result, the light-emitting points 57a to 57d emit light simultaneously, and as shown in FIG.
The beam spots 75a to 75d corresponding to d
4a. Here, due to the arrangement of the optical system as described above, the laser beams emitted from the respective light emitting points 57a to 57d of the multi-beam laser diode 36 are converted into substantially parallel light beams by the collimator lens 38, and all four laser beams are emitted. Is condensed and imaged on the imaging surface 74a by the condensing lens 73, and the imaging surface 7
It is possible to measure the positions of the beam spots 75a to 75d on 4a with high accuracy. The positions of the beam spots 75a to 75d can be obtained, for example, by calculating the position of the center of gravity as follows.

FIG. 15 shows a state where the beam spot 75a formed on the image pickup surface 74a is enlarged. When each pixel of the imaging surface 74a defined by the code Z _ij, defining the magnitude of the output signal of the pixel Z _ij by the code W _{ij,
Z 1j, Z 2j, ...,} Z ij, ..., Z nj denotes pixels arranged in the main scanning direction _{Q 1, W 1j, W 2j} , ..., W ij, ..., W
_nj is the pixel _{Z 1j, Z 2j, ...,} Z ij, ..., means the output of the _{Z nj, Z i1, Z i2} , ..., Z ij, ..., Z im are arranged in the sub-scanning direction Q ₂ , W _i1 , W _i2 ,..., W
_ij, ..., W _im is the pixel _{Z i1, Z i2, ...,} Z ij, ..., Z
Means each output of _im . Note that the subscript i (an integer from 1 to n) means that it corresponds to the i-th counting from the reference point O to the left, and the subscript j (an integer from 1 to m) indicates the reference point O
It means that it corresponds to the j-th number from the top.

The pixels Z _1j , Z arranged in the main scanning direction Q _{1
2j, ..., Z ij, ...} , sum of the output signals of the _{Z nj W j (W j =} W
_{1j + W 2j + ... + W} ij + ... + W nj) sequentially when obtaining the sub-scanning direction Q ₂ j = 1 through j = m, it is possible to obtain a sub-scanning direction of the beam intensity distribution curve B _2. The pixels Z _i1 , Z _i2 ,..., Z _ij , arranged in the sub-scanning direction Q ₂
..., the sum of the output signals of _{Z im W i (W i =} W i1 + W i2 + ... +
W _ij + ... + W _im) to the determined sequential in the main scanning direction Q ₁ from i = 1 to i = n, it is possible to obtain a beam intensity distribution curve B ₁ in the main scanning direction.

[0064] Figure 1 relative to the beam intensity distribution curve B ₁
6, the threshold value P _1h is set, and the addresses y _i1 and y _i2 of the pixels in the main scanning direction corresponding to the intensity crossing the threshold value P _1h are specified, and the arithmetic mean of the addresses y _i1 and y _i2 is calculated. _Find the address _yim of the corresponding pixel (im = (i1 + i2) / 2, im:
integer). The position of the pixel at this address y _im is _designated as beam spot 7
The center of gravity position in the main scanning direction of 5a and (center position) G _y, the position of the pixels determined in the same manner with respect to the beam intensity distribution curve B ₂ barycentric position in the sub-scanning direction (center position) and G _x, thereby beam gravity center position G (G _x, G _y) of interest 75a is defined. The threshold value P _1h is calculated as P _1h = P _max / e ² using the peak intensity P _max and the natural logarithm e.

In order to calculate the position of the center of gravity based on the overall shape of the beam spot on the imaging surface 74a as described above, the beam spots 75a to 75-7 on the imaging surface 74a are required.
It is desirable in terms of measurement accuracy that the optical system is configured so that each area of 5d is ten times or more the area of one pixel.

That is, as shown in FIG.
4a, the diameter of the beam spot in the main scanning direction is W
m, the diameter in the sub-scanning direction is Ws, the oscillation wavelength of the multi-beam laser diode 36 is λ, the beam diameter of the laser beam in the main scanning direction after passing through the opening 41b of the slit 41 is Dm ′, Assuming that the beam diameter is Ds ′, Wm = (f ₁ × λ) / (π × Dm ′) Ws = (f ₁ × λ) / (π × Ds ′), and Wm and Ws are π × Wm × Ws> The optical system of the adjusting device 72 is designed to satisfy (area of one pixel) × 10 3.

[0067] The light-emitting point 57a and the light emitting point 57d and the main scanning direction of the pitch shift amount of P _LDAm, the light emitting point 57a and the sub-scanning direction between the light emitting point 57d pitch shift amount P _LDAs, on the imaging surface 74a The pitch in the main scanning direction between the beam spot 75a and the beam spot 75d is P _ccdm , and the imaging surface 7
_Assuming that the pitch in the sub-scanning direction between the beam spot 75a and the beam spot 75d on 4a is P _ccds , P _ccdm = (f ₁ / fco) × P _LDAm P _ccds = (f ₁ / fco) × P _LDAs holds. Using P _ccdm and P _ccds , the total length Lm in the horizontal direction (main scanning direction), the total length Ls in the vertical direction (sub-scanning direction) of the imaging surface 74a, and the number N of light emitting points (N = 4 in this case), The magnification of the optical system is set so that the following equation is satisfied.

When the magnification of the optical system is set as described above, the beam spot 57a and the beam spot 57d protrude from the imaging surface 74a. P _ccdm × (N−1) + Wm <Lm P _ccds × (N−1) + Ws <Ls Instead, one CCD 74 has four light-emitting points 57a-5
The evaluation of 7d can be performed simultaneously, and the cost of the adjusting device 72 can be reduced.

Further, when the light emitting points 57a to 57d are caused to emit light at the same time, the following settings are made so that the light emitting outputs of the light emitting points 57a to 57d are substantially equal.

First, any of the light emitting points 57a to 57d
And the output of the CCD 74 associated with the emission
And the reference output P₁And Next, its already luminous
Of the remaining light-emitting points
When one of them emits light, the output of CCD 74 is the reference
Output P₁Light on the circuit board 32 so as to be twice
Adjust the volume. This light intensity adjustment is applied to the remaining two
The light emitting points 57a to 57d
When light is emitted, the output of the CCD 74 becomes the reference output P ₁4 times
Set so that Generally, as shown in FIG.
In addition, when the number of light emitting points during light emission is N, the detection output is
Force P₁May be set to be N times as large as.

When the light amount adjustment is performed in this manner, the imaging surface 74
The intensity of the beam spots 75a to 75d on “a” can be made constant, and the positions of the beam spots 75a to 75d can be detected accurately.

When the positions of the beam spots 75a to 75d on the image pickup surface 74a are detected as described above, one of them, for example, the main scanning of the other beam spots 75b, 75c, 75d with reference to the beam spot 75a. The direction deviation amounts Y ₂ , Y ₃ , and Y ₄ can be detected. The deviation amount in the main scanning direction corresponds to the deviation from the virtual straight line L ₂ of the light emitting point 57 a to 57 d, in this embodiment, is the shift amount of Y _2, Y _3, Y ₄ position data.

(3) Light emission timing data calculation step / storage step Considering the case where the light source unit 19 is attached to the housing 60 and installed in the scanning optical system, the shift amounts Y ₂ , Y ₃ , Y obtained in the previous step are considered. Each light emitting point 57b is proportional to ₄
Write timing (light emission timing) of 57c and 57d
If the position is not shifted, the writing position on the photosensitive member 68 is shifted between the laser beams in the main scanning direction. Therefore, the optical magnification of the scanning optical system is M, the optical magnification of the adjusting device 72 is m, the beam scanning speed on the photosensitive surface 68a of the photosensitive member 68 is v, and the writing timing of the light emitting point 57b with respect to the light emitting point 57a. Is required to be delayed by the time t ₂ , t ₂ = (Y ₂ × M / m) / v is calculated, and this is stored in the EEPROM 34 as light emission timing data for the light emission point 57b. Similarly, the light emission timing data (delay time) t _{3 for} the light emitting point 57 c and the light emission timing data (delay time) t ₄ for the light emitting point 57 d are respectively expressed as t ₃ = (Y ₃ × M / m) / v t ₄ = (Y ₄ × M / m) / v, and these are stored in the EEPROM 34 as light emission timing data for the light emission point 57b.

After the completion of this step, through a final inspection,
The light source unit 19 is completed as a product. Note that t
Calculation of ₂ , t ₃ , and t ₄ may be performed by the adjustment device 72 or by the CPU 33 of the light source unit 19.

[Operation of Light Source Unit in Image Forming Apparatus] As described above, the output beam of the light source unit 19 mounted on the housing 60 and incorporated in the image forming apparatus is:
The photosensitive member 6 is formed by the polygon mirror 61 and the fθ lens 62.
8 scans the photosensitive surface 68a in the main scanning direction. Before scanning on the photosensitive surface 68a, the light is reflected by the mirror 76 provided on the housing 60 and enters the synchronization detecting circuit 77. The circuit board 32 of the light source unit 19 is electrically connected to the synchronization detection circuit 77, and controls the light emission of the multi-beam laser diode 36 in response to the detection signal from the synchronization detection circuit 77.

That is, the CPU 33 of the circuit board 32
Until the detection signal from the synchronization detection circuit 77 is received, only the light emitting point 57a emits light. When the laser beam from the light emission point 57a enters the synchronization detection circuit 77 and receives the detection signal from this point, it is stored in the EEPROM 34 in advance. After the elapse of the reference time t, writing to the photoconductor 68 by the light emitting point 57a is started. Further, the CPU 33 starts writing by the light emitting point 57b after a lapse of time (t + t ₂ ) after receiving the detection signal, and receives the detection signal for a time (t + t ₂ ).
After the elapse of ₃ ), the writing by the light emitting point 57c is started, and after the time (t + t ₄ ) from the reception of the detection signal, the writing by the light emitting point 57b is started. This allows
Despite the deviation from the virtual straight line L ₂ of the light emitting point 57 a to 57 d, the beam spot (image information) which should be aligned originally on the photosensitive surface 68a in the sub-scanning direction 76 as such alignment as shown in FIG. 19 I do.

In the light source unit according to this embodiment,
Since the multi-beam laser diode 36 emits light based on the position data Y ₂ , Y ₃ , Y ₄ corresponding to the deviation of each of the light emitting points 57 a to 57 d from the virtual straight line L ₂ , the adjusting device 72 for obtaining the position data Is cheaper than an adjusting device for detecting a time shift of the order of ns, and its position data is stored in advance, so that the beam spots 76 are arranged in a predetermined direction on the photosensitive member 68. Adjustments can be made in advance (before shipping to the market).

Further, data t ₂ , t ₃ ,... Relating to the light emission timing calculated based on the position data Y ₂ , Y ₃ , Y ₄ .
Since the light source unit 19 itself has the EEPROM 34 in which t ₄ is stored in advance, the beam spot 76 is
It is possible to replace only the light source unit 19 without making an adjustment for arranging in the predetermined direction on the market 8, and it is possible to greatly reduce the labor and cost required for replacing the multi-beam laser diode 36.

Further, since the light emission is performed based on the data stored in advance as described above, the design of the scanning optical system using the light source unit 19 or the light source unit 19 itself does not limit the light emission timing. Degree of freedom can be increased.

On the other hand, the EEP
The light emission timing data (or position data) stored in the ROM 34 is affixed to the light source unit 19 as a barcode label 78 having a barcode symbol obtained by barcoding the data, as shown in FIGS. .

The bar code label 78 includes, in addition to the bar code symbol, light emission timing data (or position data).
Is numerically described, and when the light source unit 19 is replaced due to wear in the market after shipment, a serviceman or a user can visually confirm the positional deviation.

FIG. 20 is a block diagram relating to displacement control of each of the light emitting points 57a to 57d using a bar code symbol.
4 is a flowchart of a storage process of the EEPROM 34. FIG.

In FIG. 20, the EEPROM 34 has
The light emission timing data obtained in the light emission timing data calculation step described above can be stored according to various conditions (routes).

The condition at this time is that the light source unit 19
Production process (from step 10 in FIG. 21), the production process of the image forming apparatus (from step 20 in FIG. 21), at the time of installation in the market, confirmation of maintenance, etc., or the light source unit 1
At the time of replacement due to wear of No. 9 (after step 30 in FIG. 21), etc. are considered. In addition, as the storage route, direct writing immediately after the calculation step during the production of the light source unit 19,
An input from a reading device (bar code reader) 79 that reads a bar code symbol, an input from a ten key 80 of an existing operation panel of the image forming apparatus, a communication input from a communication terminal (or a server) 81, and the like can be considered.

The light emission timing data stored in the EEPROM 34 is output to the CPU 33 when the image forming apparatus is started. The CPU 33 controls the multi-beam laser diode 3 based on the emission timing data.
The light is emitted while controlling the light emission timing of each of the light emission points 57a to 57d of No. 6. The data stored in the EEPROM 34 may be used as position data, and the CPU 33 may calculate light emission timing data based on the position data to control light emission.

Next, the storage route in each step will be described.

(Step 10) In the step of producing the light source unit 19 in the step 10, the mounting bracket 20
Then, the base member 35 and the circuit board 32 are assembled, and the light source unit 19 is assembled.

(Step 11) The data is stored in the EEPROM 34 through the above-described position data acquisition step and the emission timing data calculation / storage step (Step 2 described later).
2 may be performed), and the process proceeds to step 12.

(Step 12) In step 12, based on the light emission timing data obtained in step 11, a barcode symbol 78 having a barcode symbol obtained by converting the data into barcodes and numerical data obtained by digitizing the data is created. The bar code label 78 is attached to the light source unit 19
Paste in. From this state, for example, the light source knit 19
If the light source unit 19 is assembled in the image forming apparatus on the market as a replacement part due to wear or the like, the process proceeds to step 30 when the light source unit 19 is assembled in the image forming apparatus production process.

(Step 20) In step 20, the image forming apparatus such as the housing 60 and the photoreceptor 68 is assembled, and the process proceeds to step 21 in a predetermined process.

(Step 21) In step 21, the light source unit 19 is incorporated in the housing 60, and the flow proceeds to step 22.

(Step 22) At step 22, at least at the time when the assembly (including the power supply system) relating to the scanning optical system is completed, the light emission timing data obtained through the position data acquisition step and the light emission timing data calculation / storage step is stored in the EEPROM 34. And the process proceeds to step 23. Note that the EEPRO of the light emission timing data
As a method of storing data in the M34, the barcode reading device reads the barcode symbol of the barcode label 78 and writes the data in the EEPROM 34, and also inputs the numerical data of the barcode label 78 using the ten keys of the image forming apparatus. Writing to the EEPROM 34, or
Writing to the EEPROM 34 using the network RAN in the image forming apparatus production factory may be considered.

(Step 23) In step 23, after the image forming apparatus is tested at the time of shipment or after the market is sold, the EEPRO is triggered by turning on the main power supply of the image forming apparatus.
The light emission timing data is output from the M34 to the CPU 33, and the light emission of each of the light emission points 57a to 57d is controlled.

(Step 30) In step 30, if it is necessary to replace the light source unit 19 due to an artificial judgment at the time of maintenance in the market or an occasional occurrence of a failure error signal, etc. After removing the light source unit 19 assembled in the housing 60, a new light source unit 19 is incorporated in the housing 60 and the process proceeds to step 31.

(Step 31) In step 31, after the confirmation of the incorporation is completed, for example, the numerical data written together with the bar code symbol on the bar code label 78 is artificially read, and the 10 key 80 of the image forming apparatus is used. The numerical data is input and new light emission timing data is EE
The data is output to the PROM 34 and the process proceeds to step 22.

Although the specific embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments.

For example, after the multi-beam laser diode 36 is once rotated so that the arrangement direction Q _{4 of} the light emitting points 57 a to 57 d (see FIG. 9) is aligned with the direction in which the virtual straight line L ₂ extends, the light emitting points 57 a the deviation from the virtual straight line L ₂ of ~57d may be performed the above-described adjusted to compensate.

Further, for example, the CPU 3
3 provided in the housing 60 of the image forming apparatus separately from the light source unit 19, and an EEPROM 3 as storage means.
4 is provided on the housing 60 of the image forming apparatus separately from the light source unit 19; a bar code label 78 is provided on the housing 60 of the image forming apparatus separately from the light source unit 19 (see FIG. 10); EE
The PROM 34 and the barcode label 78 may be provided in the light source unit 19 or the housing 60 in combination.

At this time, for example, only the bar code label 78 is provided in the light source unit 19, and the CPU 33 and the EEPROM are used.
When the OM 34 is provided in the housing 60, the existing control means and storage means in the image forming apparatus are replaced with the CPU 33 and the EEP.
It can also be used as the ROM 34, so that the cost of parts can be reduced.

The CPU 33 and the bar code label 7
When the light source unit 8 is provided in the light source unit 19 and the EEPROM 34 is provided in the housing 60, the EEPROM 34 can be used not only by the existing storage means provided on the operation panel or the like of the image forming apparatus, but also by the image forming apparatus. When connected to a telecommunication line (including a network line such as a RAN in a production factory) such as in the case of a facsimile, the line is used to
It becomes possible to change the position data and the light emission timing data for the storage means on the image forming apparatus main body side in place of the EPROM.

The above-described CPU 33 and EEPROM 3
When the light source unit 4 is separated from the light source unit 19, it is needless to say that the light source unit 19 is electrically connected to the light source unit 19 and is controlled.

[0102]

As described above, in the light source unit according to the first aspect, when a multi-beam laser diode and an optical lens are installed in a scanning optical system, a plurality of laser beams transmitted through the optical lens are provided. By emitting light based on position data corresponding to a deviation from the virtual straight line of each of the light emitting points stored in advance so that the beam spots scan the recording medium while being arranged in a predetermined direction, the virtual position of each light emitting point Since each light-emitting point emits light based on the position data corresponding to the deviation from the straight line, the adjustment device for obtaining the position data is less expensive than the adjustment device for detecting a time deviation of the order of ns. Since the position data is stored in advance, adjustment for arranging the beam spots in a predetermined direction on the recording medium can be performed in advance. In addition, since light emission is performed based on the data stored in advance in this manner, the design of the scanning optical system using the light source unit or the light source unit itself does not limit the light emission timing, and the design flexibility is increased. be able to.

[0103] The light source unit according to claim 2, further comprising storage means for storing in advance the position data or light emission timing data corresponding to the light emission timing of each of the light emission points calculated based on the position data, The light emission at each of the light emission points is controlled based on any data stored in the storage means.

According to a third aspect of the present invention, there is provided a light source unit that includes control means for controlling light emission at each of the light emitting points based on any data stored in the storage means.

The light source unit according to the fourth aspect is provided with a bar code label obtained by converting any of the position data and the light emission timing data into a bar code.

In the light source unit according to the fifth aspect, the bar code label includes numerical data obtained by digitizing either the position data or the light emission timing data.

According to the light source unit of any one of claims 2 to 5, the storage means in which the position data or the light emission timing data corresponding to the light emission timing calculated based on the position data is stored in advance is used as the light source unit. Since the unit itself is provided, it is possible to replace only the light source unit without making adjustments to align the beam spot in a predetermined direction on the recording medium in the market, greatly reducing the labor and cost required for replacing the multi-beam laser diode. Can be reduced.

An image forming apparatus according to a sixth aspect has the light source unit according to any one of the first to fifth aspects.

According to a seventh aspect of the present invention, there is provided the image forming apparatus having the light source unit according to the first aspect, wherein the light source unit corresponds to the position data or the light emission timing of each of the light emitting points calculated based on the position data. A storage unit that stores in advance the light emission timing data to be performed is provided separately from the light source unit, and the light emission at each of the light emitting points is controlled based on any data stored in the storage unit.

According to an eighth aspect of the present invention, there is provided the image forming apparatus having the light source unit according to the first aspect, wherein the light source unit corresponds to the position data or the light emission timing of each of the light emitting points calculated based on the position data. The light source unit is provided with storage means for storing light emission timing data in advance separately from the light source unit, and control means for controlling light emission at each light emitting point based on any data stored in the storage means is provided in the light source unit. I have one.

An image forming apparatus according to a ninth aspect has the light source unit according to the first aspect, and the light source unit corresponds to the position data or the light emission timing of each of the light emitting points calculated based on the position data. And a control unit for controlling light emission at each of the light emitting points based on any data stored in the storage unit, separately from the light source unit.

According to a tenth aspect of the present invention, there is provided the image forming apparatus having the light source unit according to the second aspect, and controlling the light emission of each of the light emitting points based on any data stored in the storage means. The control means for performing the control is provided separately from the light source unit.

According to the image forming apparatus of the present invention, a bar code label having a bar code symbol obtained by converting any of the position data or the light emission timing data into a bar code is integrated with the light source unit. Prepare separately.

In the image forming apparatus according to the twelfth aspect, on the bar code label, numerical data obtained by digitizing either the position data or the light emission timing data is described.

In the image forming apparatus according to the thirteenth aspect, the bar code symbol is read by a reading device,
Input means for inputting a result read by the reading device to the storage means;

According to a fourteenth aspect of the present invention, the image forming apparatus further comprises an input means for inputting the numerical data to the storage means.

In the image forming apparatus according to the present invention, the input means is an electric communication line.

In the image forming apparatus according to the sixteenth aspect, the input means is a ten-key provided on the image forming apparatus main body.

[0119] In the image forming apparatus according to the seventeenth aspect, the light source unit is detachable.

According to the image forming apparatus described in any one of claims 6 to 17, the effects of any one of claims 1 to 5 can be enjoyed in the image forming apparatus.

In the method for producing a light source unit according to the eighteenth aspect, a plurality of laser beams transmitted through the optical lens are projected on the light receiving element, and the position data corresponding to the deviation of each light emitting point from the virtual straight line is obtained. A position data obtaining step of obtaining the position data; and a storage step of storing the position data obtained in the position data obtaining step in a storage unit.

In the method for producing a light source unit according to the nineteenth aspect, a plurality of laser beams transmitted through the optical lens are projected on the light receiving element, and position data corresponding to the deviation of each light emitting point from the virtual straight line is obtained. Obtaining position data obtaining step, based on the position data so that the beam spots of a plurality of laser beams passing through the optical lens are scanned on the recording medium while being aligned in a predetermined direction when the light source unit is installed in the scanning optical system. The method includes a light emission timing data calculation step of calculating light emission timing data regarding a light emission timing of each light emission point, and a storage step of storing the light emission timing data obtained in the light emission timing data calculation step in a storage unit.

According to a twentieth aspect of the present invention, there is provided a method for producing a light source unit, wherein the light source unit has a bar code symbol converted into a bar code corresponding to data obtained in either the position data obtaining step or the light emission timing data calculating step. A label creating step for creating a bar code label, an attaching step for attaching the bar code label to the light source unit or the image forming apparatus, and a storage means in the storing step by reading the bar code symbol attached in the attaching step And the light emission timing data are stored.

According to the method of manufacturing a light source unit of the present invention, it is possible to adjust the arrangement of the beam spots in a predetermined direction on the recording medium by coping with the deviation of each light emitting point from a virtual straight line. Since the position data to be obtained is obtained, the adjusting device is inexpensive as compared with the case of detecting the time shift of the ns order, and the data on the light emission timing calculated based on the position data is stored in the storage means. The adjustment can be completed in advance (before the light source unit is shipped to the market). Further, since the light emission of the manufactured light source unit is performed based on the data stored in advance in this way, whether the scanning optical system in which the light source unit is used or the design of the light source unit itself limits the light emission timing. And the degree of freedom of design can be increased.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a light source unit according to the present invention.

FIG. 2 is a front view showing the mounting bracket of FIG. 1;

FIG. 3 is a rear view showing the mounting bracket of FIG. 1;

FIG. 4 is a plan view showing the mounting bracket of FIG. 1;

FIG. 5 is an exploded perspective view showing the base member of FIG. 1 in an enlarged manner.

FIG. 6 is an exploded perspective view showing a state where the base member of FIG. 5 is viewed from the back side.

FIG. 7 is a front view showing a state where the light source unit of FIG. 1 is assembled.

FIG. 8 is a rear view showing a state where the light source unit of FIG. 1 is assembled.

FIG. 9 is an explanatory diagram showing the multi-beam laser diode of FIG. 1 in an enlarged manner.

FIG. 10 is an explanatory diagram showing a housing before a light source unit is attached.

FIG. 11 is an explanatory diagram showing a housing to which a light source unit is attached.

FIG. 12 is an explanatory diagram showing an adjusting device.

FIG. 13 is an explanatory diagram showing an optical arrangement of the adjustment device of FIG. 12;

14 is an explanatory diagram illustrating a beam spot on an imaging surface of the adjustment device in FIG.

FIG. 15 is an explanatory diagram showing the beam spot of FIG. 14 in an enlarged manner.

FIG. 16 is an explanatory diagram showing a concept of obtaining a center of gravity from a beam intensity distribution curve.

FIG. 17 is an explanatory diagram illustrating a relationship between a diameter of a beam spot and a dimension of an imaging surface.

FIG. 18 is an explanatory diagram showing a relationship between the number of light emitting points during light emission and a laser beam output.

FIG. 19 is an explanatory diagram illustrating a beam spot on a photosensitive member of the image forming apparatus.

FIG. 20 is a block diagram relating to shift control of each light emitting point using a bar code symbol.

FIG. 21 is a flowchart of a process of storing data in a storage unit.

FIG. 22 is an explanatory diagram showing a schematic configuration of a conventional scanning optical system.

FIG. 23 is an explanatory diagram showing a beam spot on the surface of the photoconductor of the scanning optical system of FIG. 22;

FIG. 24 is an enlarged front view showing the multi-beam laser diode of FIG. 22;

FIG. 25 is an explanatory diagram showing a deviation between a direction in which a virtual straight line extends in the multi-beam laser diode of FIG.

[Explanation of symbols]

 19 light source unit 33 CPU (control means) 34 EEPROM (storage means) 36 multi-beam laser diode 38 collimator lens 49 stem 57a light-emitting point 57b light-emitting point 57c light-emitting point 57d light-emitting point 58 cutout Reference numeral 60: Housing 68: Photoconductor (recording medium) 76: Beam spot 78: Bar code label L: Virtual straight line

Continued on the front page F term (reference) 2C362 AA07 AA11 AA12 AA43 AA48 BA57 BA68 BA70 BA71 BB37 BB43 2H045 AA01 BA23 BA33 CA98 DA02 DA04 5F073 AB05 AB25 AB27 AB29 BA07 FA30

Claims (20)

[Claims] 1. A multi-beam laser diode in which a plurality of light emitting points are designed on a virtual straight line defined by a notch formed in a stem, and a plurality of laser beams emitted from each of the light emitting points are converted into a parallel light beam. A light source unit provided in a scanning optical system with an optical lens, wherein a beam spot of a plurality of laser beams transmitted through the optical lens when the multi-beam laser diode and the optical lens are installed in the scanning optical system. A light source unit that emits light based on positional data corresponding to a shift of each of the light emitting points from the virtual straight line stored in advance so as to scan a recording medium while being arranged in a predetermined direction. 2. A storage device in which the position data or light emission timing data corresponding to the light emission timing of each of the light emission points calculated based on the position data is stored in advance. The light source unit according to claim 1, wherein light emission of each of the light emitting points is controlled based on the light emission point. 3. The light source unit according to claim 2, further comprising control means for controlling light emission at each of said light emitting points based on any data stored in said storage means. 4. The light source unit according to claim 2, further comprising a bar code label obtained by converting any one of the position data and the light emission timing data into a bar code. 5. The light source unit according to claim 4, wherein the bar code label includes numerical data obtained by digitizing either the position data or the light emission timing data. 6. An image forming apparatus comprising the light source unit according to claim 1. 7. A storage unit having the light source unit according to claim 1 and storing in advance said position data or light emission timing data corresponding to the light emission timing of each of said light emission points calculated based on said position data. An image forming apparatus which is provided separately from a light source unit and controls light emission at each of the light emitting points based on any data stored in the storage means. 8. A storage unit having the light source unit according to claim 1, wherein said storage means stores in advance said position data or light emission timing data corresponding to the light emission timing of each of said light emission points calculated based on said position data. An image forming apparatus comprising: a light source unit; and a light source unit integrally provided with control means for controlling light emission at each of the light emitting points based on any data stored in the storage means. apparatus. 9. A storage means having the light source unit according to claim 1, wherein said storage means stores in advance said position data or light emission timing data corresponding to the light emission timing of each of said light emission points calculated based on said position data. An image forming apparatus comprising: a control unit that controls light emission of each of the light emitting points based on any data stored in a storage unit, separately from the light source unit. 10. A light source unit according to claim 2, wherein control means for controlling light emission of each light emitting point based on any data stored in said storage means is provided separately from said light source unit. An image forming apparatus comprising: 11. A light source unit, wherein a bar code label having a bar code symbol obtained by converting any of the position data and the light emission timing data into a bar code is provided integrally with or separately from the light source unit. The image forming apparatus according to claim 10. 12. The image forming apparatus according to claim 11, wherein the bar code label includes numerical data obtained by digitizing either the position data or the light emission timing data. . 13. An image forming apparatus according to claim 11, further comprising input means for reading said bar code symbol by a reading device and inputting a result read by said reading device to said storage means. . 14. An image forming apparatus according to claim 12, further comprising input means for inputting said numerical data to said storage means. 15. An image forming apparatus according to claim 13, wherein said input means is a telecommunication line. 16. An image forming apparatus according to claim 14, wherein said input means is a ten-key provided on an image forming apparatus main body. 17. The image forming apparatus according to claim 7, wherein said light source unit is detachable. 18. A multi-beam laser diode in which a plurality of light emitting points are designed on a virtual straight line defined by a notch formed in a stem, and a plurality of laser beams emitted from each of the light emitting points are converted into a parallel light beam. An optical lens, wherein the multi-beam laser diode produces a light source unit that emits light in accordance with an output signal of a control unit, wherein the plurality of laser beams transmitted through the optical lens are projected onto a light receiving element, and A position data obtaining step of obtaining position data corresponding to a deviation of each light emitting point from the virtual straight line; and a storage step of storing the position data obtained in the position data obtaining step in a storage unit. Light source unit production method. 19. A multi-beam laser diode in which a plurality of light-emitting points are designed on a virtual straight line defined by a notch formed in a stem, and a plurality of laser beams emitted from each of the light-emitting points are converted into a parallel light beam. An optical lens, wherein the multi-beam laser diode produces a light source unit that emits light in accordance with an output signal of a control unit, wherein the plurality of laser beams transmitted through the optical lens are projected onto a light receiving element, and A position data obtaining step of obtaining position data corresponding to a deviation of each light emitting point from the virtual straight line; and a beam spot of a plurality of laser beams transmitted through the optical lens when the light source unit is installed in a scanning optical system. The light emission timing of each of the light emission points is determined based on the position data so as to scan the recording medium while being arranged in a predetermined direction. A light emission timing data calculation step of calculating light emission timing data relating to the lighting, and a storage step of storing the light emission timing data obtained in the light emission timing data calculation step in a storage unit. . 20. A label producing step of producing a bar code label having a bar code symbol converted into a bar code corresponding to the data obtained in either the position data obtaining step or the light emission timing data calculating step. An attaching step of attaching a barcode label to the light source unit or the image forming apparatus, and reading the barcode symbol attached in the attaching step to read the position data or the position data to the storage unit in the storing step. 20. The method according to claim 18, wherein light emission timing data is stored.