JP3874999B2 - Light source unit, image forming apparatus using light source unit, and method for producing light source unit - Google Patents

Description

[0001]
BACKGROUND 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]
[Prior art]
2. Description of the Related Art Image forming apparatuses such as digital copying machines and laser printers are known in which a scanning optical system is mounted with a laser type. In addition, as a light source used in such a laser scanning optical system, a light source using a multi-beam laser diode is becoming mainstream in order to meet the demand for higher accuracy and higher speed of writing.
[0003]
FIG. 22 schematically shows a laser scanning optical system, where 1 is a light source unit, 2 is a polygon mirror, 3 is an fθ lens, and 4 is a photoreceptor. The light source unit 1 includes a multi-beam laser diode 5 and a collimator lens 6, and the multi-beam laser diode 5 emits a laser beam P from light emitting points 7a to 7d (see FIG. 24). The laser beam P is converted into a parallel light beam by the collimator lens 6 and reflected by the rotating polygon mirror 2 to cause the surface 4a of the photosensitive member 4 to pass through the main scanning direction Q.₁To scan.
[0004]
As shown in FIG. 23, the laser beam P from two adjacent light emitting points travels on the surface 4a of the photoreceptor 4 in the main scanning direction Q.₁Sub-scanning direction Q orthogonal to₂A predetermined pitch X₁ And a beam spot 8 is formed. Here, since the multi-beam laser diode 5 has four light emitting points 7a to 7d, the four laser beams P simultaneously scan the surface 4a of the photosensitive member 4 to write image information.
[0005]
As shown in FIG. 24, the multi-beam laser diode 5 includes a rectangular parallelepiped laser diode chip 9, a base 10 to which the laser diode chip 9 is attached, and a stem 11. The stem 11 is formed with a pair of V-shaped cutouts 12 and 12 as viewed from the front, and the light emitting points 7a to 7d are virtual straight lines L obtained by connecting the sharp portions 12a and 12a of the cutouts 12 and 12.₁It is provided on the front surface 13 of the laser diode chip 9 so as to be positioned above the design. Accordingly, a direction in which a straight line that approximately connects the light emitting points 7a to 7d extends (hereinafter referred to as an “arrangement direction”) Q._Three Considering the arrangement direction Q_ThreeIs theoretically a straight line L₁The light emitting points 7a to 7d are actually imaginary straight lines L due to errors in manufacturing the multi-beam laser diode 5 or the like.₁Generally, it is shifted from the top, and as shown in an exaggerated manner in FIG._ThreeIs the virtual straight line L₁Slightly inclined to₁have.
[0006]
Conventionally, in this type of multi-beam laser diode 5, it is difficult to narrow the interval between the light emitting points 7a to 7d for reasons of manufacturing technology, and the arrangement direction Q of the light emitting points 7a to 7d is difficult._ThreeIn the sub-scanning direction Q₂If the laser beam P is projected onto the photoconductor 4 in a state matched to the above, the sub-scanning direction Q₂Pitch X₁As a result, the desired image quality could not be obtained. Therefore, for example, as described in JP-A-57-8887 and JP-A-9-96771, the arrangement direction Q of the light emitting points 7a to 7d is described._ThreeSub-scanning direction Q₂The pitch X₁In the sub-scanning direction Q₂Writing density (recording density) was improved (see FIG. 1 of JP-A-57-8887 and FIG. 3 of JP-A-9-96771).
[0007]
[Problems to be solved by the invention]
However, in the configuration described in Japanese Patent Laid-Open No. 57-8887, each beam spot 8 on the photoconductor 4 is in the sub-scanning direction Q.₂In order to adjust so that the polygon mirror 2 is rotated, the time lag of the laser beam P from each of the light emitting points 7a to 7d with the polygon mirror 2 rotated (the laser beam P from each of the light emitting points 7a to 7d₁The time lag in reaching the predetermined position of the above shall be detected. Since the time lag of each laser beam P must normally be detected in the order of ns (nanoseconds), an oscilloscope or the like is required as an adjustment jig (hereinafter referred to as “adjustment device”). There is a problem that the apparatus becomes expensive.
[0008]
The light source unit 1 including a semiconductor laser is a consumable item, and is a replacement part in the market for copying machines and laser printers. However, in the configuration described in the publication, the light source unit 1 is separated from the scanning optical system. Since adjustment cannot be performed, when the light source unit 1 is replaced, an expensive adjustment device as described above is brought into the market and only the light source unit 1 is replaced and then the adjustment is performed, or not only the light source unit 1 but also the polygon mirror 2 or the like. It is necessary to replace the entire scanning optical system including For this reason, it takes time and cost to replace the light source unit, which causes trouble in terms of serviceability for the user.
[0009]
On the other hand, even with the configuration described in Japanese Patent Laid-Open No. 9-96771, it is necessary to detect the laser beam P while the polygon mirror 2 is rotated. In order to detect P with a single sensor, there is a problem of lack of versatility due to restrictions on dimensional relationships. In particular, in the development of the multi-beam laser diode 5 in which the intervals between the light emitting points 7a to 7d are dense, the arrangement direction Q of the light emitting points 7a to 7d is being developed._ThreeIn the sub-scanning direction Q₂It is possible to arrange the multi-beam laser diode 5 in a state adapted to the above, but in such a case, the configuration described in the same publication cannot identify and detect a plurality of laser beams P. There is a problem that adjustment cannot be performed.
[0010]
The present invention has been made in view of the above circumstances, and makes it possible to perform adjustment in advance with an inexpensive adjustment device for aligning the beam spots of a plurality of laser beams in a predetermined direction on a recording medium, and An object of the present invention is to provide a light source unit that can increase the degree of freedom of design of a scanning optical system in which the light source unit is used, an image forming apparatus using the light source unit, and a method for producing the light source unit. Yes.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problem, the light source unit according to claim 1 includes 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 the light emitting points. A light source unit provided in a scanning optical system with an optical lens that converts a plurality of laser beams emitted from the laser beam into a parallel light beam,
When the multi-beam laser diode and the optical lens are installed in the scanning optical system, beam spots of a plurality of laser beams that pass through the optical lens are stored in advance so as to scan the recording medium while being aligned in a predetermined direction. Furthermore, the gist is to emit light based on position data corresponding to the deviation of each light emitting point from the virtual straight line.
[0012]
According to the first aspect of the present invention, since 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, the adjusting device for obtaining the position data has a time shift of ns order. Since the position data is stored in advance, the adjustment for aligning the beam spot in a predetermined direction on the recording medium is possible in advance (shipment to the market). Can be done before). Since light is emitted based on the data stored in advance as described above, the design of the scanning optical system in which the light source unit is used or the light source unit itself does not limit the light emission timing, and the degree of freedom in design is increased. be able to.
[0013]
The light source unit according to claim 2 includes storage means for storing in advance the light emission timing data corresponding to the light emission timing of each of the light emission points calculated based on the position data or the position data. The gist is to control the light emission of each of the light emitting points based on any data.
[0014]
The light source unit according to claim 3 includes a control unit that controls light emission of each of the light emitting points based on any data stored in the storage unit.
[0015]
The light source unit according to claim 4 is provided with a bar code label obtained by bar-coding either the position data or the light emission timing data.
[0016]
The light source unit according to claim 5 is characterized in that numerical data obtained by digitizing any one of the position data and the light emission timing data is written together in the barcode label.
[0017]
According to the light source unit according to any one of claims 2 to 5, the light source unit itself includes storage means in which light emission timing data corresponding to the light emission timing calculated based on the position data or the position data is stored in advance. This makes it possible to replace only the light source unit without making adjustments in the market to align the beam spots in a predetermined direction on the recording medium, greatly reducing the labor and cost required to replace the multi-beam laser diode. Can do.
[0018]
A gist of an image forming apparatus according to a sixth aspect is that it includes the light source unit according to any one of the first to fifth aspects.
[0019]
An image forming apparatus according to a seventh aspect includes the light source unit according to the first aspect, and preliminarily stores the position data or light emission timing data corresponding to the light emission timing of each light emission point calculated based on the position data. The gist of the invention is that the storage means stored is provided separately from the light source unit, and the light emission of each light emitting point is controlled based on any data stored in the storage means.
[0020]
An image forming apparatus according to an eighth aspect includes the light source unit according to the first aspect, and preliminarily stores the position data or light emission timing data corresponding to the light emission timing of each light emission point calculated based on the position data. The storage means stored in the light source unit is provided separately from the light source unit, and the light source unit is integrally provided with control means for controlling the light emission of each light emitting point based on any data stored in the storage means. Is the gist.
[0021]
An image forming apparatus according to a ninth aspect includes the light source unit according to the first aspect and preliminarily stores the position data or light emission timing data corresponding to the light emission timing of each light emission point calculated based on the position data. The gist of the invention is that each of the storage means and the control means for controlling the light emission of each light emitting point based on any data stored in the storage means is provided separately from the light source unit.
[0022]
An image forming apparatus according to a tenth aspect includes the light source unit according to the second aspect, and includes a control unit that controls light emission at each light emitting point based on any data stored in the storage unit. The gist is to provide a separate unit from the unit.
[0023]
12. The image forming apparatus according to claim 11, wherein a barcode label having a barcode symbol obtained by barcode-coding any one of the position data and the light emission timing data is provided integrally with or separately from the light source unit. The gist.
[0024]
The gist of the image forming apparatus according to claim 12 is that the bar code label is accompanied by numerical data obtained by digitizing either the position data or the light emission timing data.
[0025]
According to a thirteenth aspect of the present invention, there is provided an image forming apparatus including an input unit that reads the barcode symbol by a reading device and inputs a result read by the reading device to the storage unit.
[0026]
The gist of an image forming apparatus according to claim 14 is provided with an input unit for inputting the numerical data to the storage unit.
[0027]
The gist of the image forming apparatus according to claim 15 is that the input means is a telecommunication line.
[0028]
The gist of an image forming apparatus according to claim 16 is that the input means is a numeric keypad provided in the main body of the image forming apparatus.
[0029]
The gist of an image forming apparatus according to claim 17 is that the light source unit is detachable.
[0030]
According to the image forming apparatus of the sixth aspect to the seventeenth aspect, the effect of any one of the first aspect to the fifth aspect can be enjoyed in the image forming apparatus.
[0031]
The method for producing a light source unit according to claim 18 includes: a multi-beam laser diode in which a plurality of light-emitting points are positioned on a virtual straight line defined by a notch formed in the stem; and a plurality of light-emitting points emitted from the light-emitting points. An optical lens that converts the laser beam into a parallel light beam, and the multi-beam laser diode emits light according to the output signal of the control means,
A position data acquisition step of projecting a plurality of laser beams transmitted through the optical lens onto a light receiving element to obtain position data corresponding to the deviation of each light emitting point from the virtual straight line, and the position data acquisition step And having a storage step of storing the position data in the storage means.
[0032]
The light source unit production method according to claim 19 includes 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 the stem, and a plurality of light-emitting points emitted from the light-emitting points. An optical lens that converts the laser beam into a parallel light beam, and the multi-beam laser diode emits light according to the output signal of the control means,
A position data acquisition step of projecting a plurality of laser beams transmitted through the optical lens onto a light receiving element to obtain position data corresponding to the deviation of each light emitting point from the virtual straight line, and the light source unit installed in a scanning optical system In this case, the light emission timing data relating to the light emission timing of each light emitting point is calculated based on the position data so that the beam spot of the plurality of laser beams transmitted through the optical lens is scanned on the recording medium while being aligned in a predetermined direction. And a storage step of storing the light emission timing data obtained in the light emission timing data calculation step in a storage means.
[0033]
The light source unit production method according to claim 20, wherein a barcode label having a barcode symbol barcoded corresponding to the data obtained in either the position data acquisition step or the light emission timing data calculation step is provided. A label creating step to be created, an affixing step of affixing the barcode label to the light source unit or the image forming apparatus, and the storage in the storing step by reading the barcode symbol affixed in the affixing step The gist is to store the position data or the light emission timing data in the means.
[0034]
According to the method for producing the light source unit according to any one of claims 18 to 20, the position data corresponding to the deviation of each light emitting point from the virtual straight line when performing adjustment for aligning the beam spot in a predetermined direction on the recording medium. Therefore, the adjustment device is less expensive than the case of detecting a time shift in the order of ns, and data relating to the light emission timing calculated based on the position data is stored in the storage means. It can be completed in advance (before shipment of the light source unit 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, the design of the scanning optical system in which the light source unit is used or the light source unit itself has a limitation on the light emission timing. Therefore, the degree of freedom in design can be increased.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0036]
[Configuration of light source unit]
FIG. 1 shows an exploded perspective view of a light source unit 19 according to the present invention. In FIG. 1, 20 is a mounting bracket. The mounting bracket 20 includes a bottom wall portion 21, an upright wall portion 22, and side wall portions 23 and 23.
[0037]
The bottom wall portion 21 has a pair of positioning holes 21a and 21a and through holes 21b and 21b. As shown in FIG. 2, positioning reference portions 24 and 24 are formed on the bottom surface of the bottom wall portion 21. The positioning reference portion 24 is abutted against a positioning reference portion formed in the housing 60 described later.
[0038]
The standing 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 and 26 are provided on both sides of the circular through hole 25 on the back surface of the standing wall portion 22. A reference plane (reference plane that defines the sub-scanning direction) 26a of the positioning reference section 26 is formed substantially perpendicular to a reference plane (reference plane that defines the main scanning direction) 24a of the positioning reference section 24. The pair of positioning reference portions 26 and 26 are provided with screw insertion holes 27 and 27, respectively.
[0039]
A circular fitting cylinder 28 and substrate mounting portions 29 and 30 are further provided on the back surface of the standing wall portion 22. The circular fitting cylinder 28 is formed concentrically with the circular through hole 25, and the inner diameter thereof is the same as 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 attached to the board attachment portions 29 and 30, and a CPU 33 as a control unit and an EEPROM 34 as a storage unit are provided on the circuit board 32.
[0040]
A base member 35 shown in an enlarged manner in FIG. 5 is attached to the back side of the standing wall portion 22. The base member 35 holds the multi-beam laser diode 36 and has a circular fitting cylinder 37 on the front surface. The circular fitting cylinder 37 has an outer diameter slightly smaller than the inner diameter of the circular fitting cylinder 28 and is fitted into the circular fitting cylinder 28.
[0041]
An arcuate support portion 39 that supports the collimator lens 38 is formed in the circular fitting cylinder 37. The collimator lens 38 serves to convert the laser beam emitted from the multi-beam laser diode 36 into a parallel light beam.
[0042]
The circular fitting cylinder 37 has an opening 40 at the center thereof. The laser beam is emitted toward the collimator lens 38 through the opening 40. A pair of notches 37a, 37a are formed in the circular fitting cylinder 37 with the opening 40 interposed therebetween, and a pair of engagement pieces 41a, 41a of the aperture member 41 are engaged with the pair of notches 37a, 37a. The aperture member 41 has a slit 41b extending in the horizontal direction, and a laser beam passing through the slit 41b is shaped.
[0043]
On both front sides 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 and 42 are provided with screw holes 43 and 43, respectively. Between the cylindrical fitting cylinder 37 and one positioning reference portion 42, an insertion hole 44 through which the pin 31 is inserted and used for approximate positioning of the base member 35 is formed.
[0044]
As shown in FIG. 6, a pressing plate mounting portion 46 for mounting the elastic pressing plate 45 is formed on the back side of the base member 35. The elastic pressing plate 45 has four pressing spring pieces 45a at its center, and has an engaging piece 45b and a pair of screw insertion holes 45c and 45c.
[0045]
A fitting hole 47 communicating with the opening 40 is formed in the pressing plate mounting portion 46. A cylindrical main body 48 of the multi-beam laser diode 36 is fitted into the fitting hole 47. At the rear of the fitting hole 47, a mounting reference hole 50 is formed which is slightly larger in diameter than the stem 49 of the multi-beam laser diode 36 and becomes the mounting reference for the multi-beam laser diode 36 when the stem 49 is inserted. It has been. The mounting reference hole 50 has an abutting reference surface 51 against which the front surface 49a of the stem 49 is abutted. The depth of the mounting reference hole 50 is the pressure plate at the back of the stem 49 abutted against the abutting reference surface 51. It is formed so as to protrude from the back surface of the mounting portion 46.
[0046]
Screw holes 46a, 46a are formed on both sides of the pressing plate mounting portion 46 so as to overlap the screw insertion holes 45c, 45c of the elastic pressing plate 45 with the mounting reference hole 50 therebetween. The elastic pressing plate 45 faces the back surface of the multi-beam laser diode 36 with the multi-beam laser diode 36 fitted to the base member 35, and urges and holds the multi-beam laser diode 36 with the pressing spring piece 45a. As shown, the screws 52 and 52 are inserted into the screw insertion holes 45c and 45c overlapped with the screw holes 46a and 46a, and are fixed to the base member 35 with screws.
[0047]
The assembly drawing of the light source unit 19 is shown in FIGS. 7 and 8, and details of the assembly procedure will be described later.
[0048]
[Configuration of multi-beam laser diode]
As shown in an enlarged view in FIG. 9, the multi-beam laser diode 36 includes a pedestal 53 inside a cylindrical main body 48. A rectangular parallelepiped laser diode chip 55 is attached to the attachment surface 54 of the pedestal 53. On the front surface 56 of the laser diode chip 55, four light emitting points 57a to 57d for emitting a laser beam are provided.
[0049]
The stem 49 is formed with a pair of V-shaped notches 58, 58 as viewed from the front. The light emitting points 57a to 57d are defined by the notches 58 and 58 in terms of design (obtained by connecting the sharp portions 58a and 58a of the notches 58 and 58).₂Although it should be located above, each light emitting point 57a to 57d and the virtual straight line L are actually caused by an error in manufacturing the multi-beam laser diode 36.₂In general, there is a slight gap between the two.
[0050]
The stem 49 is provided with a notch 59 that engages with the engagement piece 45 b of the elastic pressing plate 45 at a position rotated by 90 ° from the notch 58 around the center of the cylindrical main body 48. When the multi-beam laser diode 36 is attached to the base member 35, the multi-beam laser diode 36 is positioned with respect to the base member 35 by the engagement between the notch 59 and the engagement piece 45b.
[0051]
[Configuration of scanning optical system]
10 and 11 show 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 attached to the housing 60, and FIG. 11 shows a state where the light source unit 19 is attached to the housing 60. Indicates.
[0052]
The housing 60 is provided with a polygon mirror 61 and an fθ lens 62 constituting a scanning optical system. The housing 60 is provided with a positioning reference portion 63 on which the light source unit 19 is installed. The positioning reference portion 63 is formed with a pair of positioning pins 64 and 64 and a pair of screw holes 65 and 65. In the light source unit 19, the reference surfaces 24a and 24a of the positioning reference portions 24 and 24 are abutted against the reference surface 63a of the positioning reference portion 63, the positioning pins 64 and 64 are inserted into the positioning holes 21a and 21a, and the through holes 21b and Screws 66 and 66 are inserted into 21 b and screwed into screw holes 65 and 65 to be fixed to the housing 60. 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, the main scanning direction Q₁An opening 67 extending in the direction is formed. When the multi-beam laser diode 36 is driven, the laser beam P emitted from each of the light emitting points 57a to 57d is rotated by the polygon mirror 61 to rotate in the main scanning direction Q.₁, And passes through the fθ lens 62 and the opening 67 and is irradiated onto the photosensitive surface 68 a of the photosensitive drum 68. The writing position of each laser beam P on the photosensitive surface 68a is controlled by the light emission control of the multi-beam laser diode 36 as will be described later.₂To be aligned.
[0054]
[Production method of light source unit]
(1) Assembly process of light source unit
When assembling the light source unit 19, first, the base member 35 to which the multi-beam laser diode 36 is attached is fixed to an optical characteristic adjusting device (not shown), and this optical characteristic adjusting device has three axial directions (fixed). The collimator lens 38 is held by a chuck that can move with respect to the light source unit 19 in the three-axis directions of the X, Y, and Z axes shown in FIG. 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 emits light in a state where the light curable adhesive is positioned on the arcuate support portion 39, thereby collimating the lens 38. 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 the laser beam satisfy predetermined criteria. When the laser beam transmitted through the collimator lens 38 satisfies desired optical characteristics, the adhesive is cured by irradiating ultraviolet rays from above the transparent collimator lens 38, and the collimator lens 38 is attached to the arcuate support portion 39. Glue. Here, although there are four laser beams that require optical characteristic adjustment, there is only one collimator lens to be moved, and each of the four laser beams cannot be adjusted independently. After the optimum position of the collimator lens 38 is obtained, the collimator lens 38 is bonded to a position obtained by averaging the optimum positions.
[0055]
When the adhesion 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 to position the reference surfaces 42a and 42a of the positioning reference portions 42 and 42. It abuts on the reference surfaces 26a, 26a of the reference portions 26, 26. In this state, screws 69 and 69 with spring washers are inserted into the screw insertion holes 27 and 27 and screwed into the screw holes 43 and 43. Thus, the multi-beam laser diode 36 is attached to the mounting bracket 20 via the base member 35. At this time, the optical axis of the multi-beam laser diode 36 is parallel to the reference surface 24a of the positioning reference portion 24, and the virtual straight line L₂Is orthogonal to the reference plane 24a.
[0056]
To the mounting bracket 20 to which the base member 35 is attached, the circuit board 32 is attached to the board attaching portions 29 and 30 by screws 70 and 70, and the terminals 71 of the multi-beam laser diode 36 are soldered to the circuit board 32.
[0057]
(2) Position data acquisition process
Next, an imaginary straight line L of each light emitting point 57a to 57d in the multi-beam laser diode 36.₂The position data corresponding to the deviation from is obtained as unique to each light source unit 19.
[0058]
FIG. 12 schematically shows an adjustment device used for acquiring the position data. The adjusting device 72 includes a condenser lens (imaging lens) 73, a CCD 74 as an image sensor, and a reference mounting portion 75. The light source unit 19 is set in the adjustment device 72 in a state where the reference surface 24 a of the positioning reference portion 24 is abutted against the reference surface 75 a of the reference mounting portion 75.
[0059]
As shown in FIG. 13, the condenser lens 73 has a front focal length of f.₁And the rear focal distance is f₁′. The collimator lens 38 has a front focal distance of f._CO′, The rear focal length is f_COIs formed. 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 at the rear focal position of the condenser lens 73.
[0060]
In a state where the light source unit 19 is set in the adjusting device 72, first, a driving voltage is simultaneously applied to each terminal 71 of the multi-beam laser diode 36.
[0061]
Thereby, the light emitting points 57a to 57d emit light simultaneously, and as shown in FIG. 14, beam spots 75a to 75d corresponding to the light emitting points 57a to 57d are formed on the imaging surface 74a. Here, due to the arrangement of the optical system as described above, the laser beams emitted from the 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 obtained. Is condensed and focused on the imaging surface 74a by the condenser lens 73, and the positions of the beam spots 75a to 75d on the imaging surface 74a can be measured 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.
[0062]
FIG. 15 shows a state in which the beam spot 75a formed on the imaging surface 74a is enlarged. Each pixel of the imaging surface 74a is denoted by a symbol Z._ijDefined by the pixel Z_ijThe magnitude of the output signal of_ijDefined by Z_1j, Z_2j, ..., Z_ij, ..., Z_njIs the main scanning direction Q₁Means the pixels arranged in W_1j, W_2j, ..., W_ij, ..., W_nj Is the pixel Z_1j, Z_2j, ..., Z_ij, ..., Z_njMeans each output of Z_i1, Z_i2, ..., Z_ij, ..., Z_imIs the sub-scanning direction Q₂Means the pixels arranged in W_i1, W_i2, ..., W_ij, ..., W_imIs the pixel Z_i1, Z_i2, ..., Z_ij, ..., Z_imMeans each output. The subscript i (integer from 1 to n) means the i-th corresponding to the left from the reference point O, and the subscript j (integer from 1 to m) is counted from the reference point O to the upper side. It means that it corresponds to jth.
[0063]
Main scanning direction Q₁Pixels Z arranged in_1j, Z_2j, ..., Z_ij, ..., Z_njSum of output signals of W_j(W_j= W_1j+ W_2j+ ... + W_ij+ ... + W_nj) In the sub-scanning direction Q₂When j = 1 to j = m are sequentially obtained, the beam intensity distribution curve B in the sub-scanning direction₂Can be obtained. Also, the sub-scanning direction Q₂Pixels Z arranged in_i1, Z_i2, ..., Z_ij , ..., Z_imTotal output signal of W_i(W_i= W_i1+ W_i2+ ... + W_ij+ ... + W_im) In the main scanning direction Q₁Sequentially from i = 1 to i = n, the beam intensity distribution curve B in the main scanning direction₁Can be obtained.
[0064]
This beam intensity distribution curve B₁As shown in FIG._1hAnd set the threshold P_1hAddress of the pixel in the main scanning direction corresponding to the intensity across_i1, Y_i2Specify the address y_i1And address y_i2Pixel address corresponding to the arithmetic mean of_im(Im = (i1 + i2) / 2, im: integer). This address y_imThe center of gravity position (center position) G in the main scanning direction of the beam spot 75a_yAnd the beam intensity distribution curve B₂Similarly, the position of the pixel obtained for the center of gravity in the sub-scanning direction (center position) G_xThus, the gravity center position G (G of the beam spot 75a_x, G_y) Is defined. The threshold value P_1hIs the peak intensity P_maxAnd natural logarithm e
P_1h= P_max/ E²
Is calculated.
[0065]
By the way, 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 in this way, the area of each of the beam spots 75a to 75d on the imaging surface 74a is more than ten times the area of one pixel. It is desirable in terms of measurement accuracy to configure the optical system so that
[0066]
That is, as shown in FIG. 17, assuming that the diameter of the beam spot on the imaging surface 74a in the main scanning direction is Wm and the diameter in the sub-scanning direction is Ws, the oscillation wavelength of the multi-beam laser diode 36 is λ, and the opening of the slit 41 The beam diameter in the main scanning direction of the laser beam after passing through 41b is Dm ′, and the beam diameter in the sub-scanning direction is Ds ′.
Wm = (f₁× λ) / (π × Dm ′)
Ws = (f₁× λ) / (π × Ds ′)
And the Wm and Ws are
π × Wm × Ws> (area of one pixel) × 10
The optical system of the adjusting device 72 is designed to satisfy the above.
[0067]
Further, the amount of pitch deviation between the light emitting point 57a and the light emitting point 57d in the main scanning direction is set to P._LDAmThe pitch deviation amount between the light emitting point 57a and the light emitting point 57d in the sub-scanning direction is expressed as P._LDAsThe pitch in the main scanning direction between the beam spot 75a and the beam spot 75d on the imaging surface 74a is P._ccdmThe pitch in the sub-scanning direction between the beam spot 75a and the beam spot 75d on the imaging surface 74a is P_ccdsIf
P_ccdm= (F₁/ Fco) x P_LDAm
P_ccds= (F₁/ Fco) x P_LDAs
And this P_ccdm, P_ccdsUsing the total length Lm in the horizontal direction (main scanning direction) of the imaging surface 74a, the total length Ls in the vertical direction (sub-scanning direction), and the number N of light emitting points (here, N = 4), the magnification of the optical system is determined. Set so that the following equation is satisfied.
[0068]
P_ccdm× (N-1) + Wm <Lm
P_ccds× (N-1) + Ws <Ls
When the magnification of the optical system is set in this way, the beam spot 57a and the beam spot 57d do not protrude from the imaging surface 74a, and the four light emitting points 57a to 57d can be simultaneously evaluated by one CCD 74, and the adjusting device. The cost can be reduced by 72.
[0069]
Further, when the light emitting points 57a to 57d are caused to emit light simultaneously, the following setting is performed so that the light emission outputs of the light emitting points 57a to 57d are substantially equal.
[0070]
First, any one of the light emitting points 57a to 57d is caused to emit light, the output of the CCD 74 accompanying the light emission is detected, and the reference output P₁And Next, when one of the remaining light emitting points is caused to emit light with the light emitting point that has already emitted light as it is, the output of the CCD 74 becomes the reference output P.₁The amount of light is adjusted on the circuit board 32 so as to be twice as large as. This light amount adjustment is sequentially performed for the remaining two light emitting points, and when all the light emitting points 57a to 57d are caused to emit light, the output of the CCD 74 becomes the reference output P.₁It is set to be 4 times. In general, as shown in FIG. 18, when the number of light emitting points during light emission is N, the detection output is the reference output P.₁It may be set to be N times as large as.
[0071]
When the light amount is adjusted in this way, the intensity of the beam spots 75a to 75d on the imaging surface 74a can be made constant, and the positions of the beam spots 75a to 75d can be accurately detected.
[0072]
When the positions of the beam spots 75a to 75d on the imaging surface 74a are detected as described above, one of them, for example, the deviation of the other beam spots 75b, 75c, and 75d in the main scanning direction with reference to the beam spot 75a. Amount Y₂, Y_Three, Y_FourCan be detected. The amount of deviation in the main scanning direction is the imaginary straight line L of the light emitting points 57a to 57d.₂In this embodiment, the amount of deviation Y₂, Y_Three, Y_FourIs position data.
[0073]
(3) Light emission timing data calculation process / memory process
Considering the case where the light source unit 19 is attached to the housing 60 and installed in the scanning optical system, the deviation Y obtained in the previous step₂, Y_Three, Y_FourUnless the writing timing (light emission timing) of each of the light emitting points 57b, 57c, 57d is shifted by an amount proportional to, the writing position on the photosensitive member 68 is shifted in the main scanning direction between the laser beams. 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. The time t₂Just need to be delayed
t₂= (Y₂× M / m) / v
Is calculated and stored in the EEPROM 34 as light emission timing data for the light emission point 57b. Similarly, light emission timing data (delay time) t for the light emission point 57c._Three, Emission timing data (delay time) t for the emission point 57d_FourEach
t_Three= (Y_Three× M / m) / v
t_Four= (Y_Four× M / m) / v
And these are stored in the EEPROM 34 as light emission timing data for the light emission point 57b.
[0074]
After the completion of this process, the light source unit 19 is completed as a product through a final inspection. Note that t₂, T_Three, T_FourThis calculation may be performed by the adjustment device 72 or the CPU 33 of the light source unit 19.
[0075]
[Operation of light source unit in image forming apparatus]
As described above, the emitted beam of the light source unit 19 attached to the housing 60 and built in the image forming apparatus scans the photosensitive surface 68a of the photosensitive member 68 in the main scanning direction by the polygon mirror 61 and the fθ lens 62. Before scanning on the photosensitive surface 68 a, the light is reflected by the mirror 76 provided in the housing 60 and enters the synchronization detection circuit 77. The circuit board 32 of the light source unit 19 is electrically connected to the synchronization detection circuit 77, receives the detection signal from the synchronization detection circuit 77, and controls the light emission of the multi-beam laser diode 36.
[0076]
That is, the CPU 33 of the circuit board 32 emits only the light emission point 57a until receiving the detection signal from the synchronization detection circuit 77, and the laser beam from the light emission point 57a is incident on the synchronization detection circuit 77 and receives the detection signal from now on. Upon receipt, writing to the photosensitive member 68 by the light emitting point 57a is started after the reference time t stored in advance in the EEPROM 34 has elapsed. Further, the CPU 33 receives the detection signal and receives the time (t + t₂ ) Starts to be written by the light emitting point 57b, receives the detection signal, and receives time (t + t_Three) Starts to be written by the light emitting point 57c, receives the detection signal, and takes time (t + t_Four) Starts writing by the light emitting point 57b. Thereby, the virtual straight line L of the light emitting points 57a to 57d.₂Regardless of the deviation from the beam spot, beam spots (image information) 76 that should be aligned in the sub-scanning direction are aligned on the light-sensitive surface 68a as shown in FIG.
[0077]
In the light source unit according to this embodiment, the virtual straight line L of each light emitting point 57a to 57d.₂Position data Y corresponding to deviation from₂, Y_Three, Y_FourSince the multi-beam laser diode 36 emits light based on the above, the adjustment device 72 for obtaining the position data can be less expensive than the adjustment device in the case of detecting a time shift of the ns order, and the position data is previously stored. Since it is stored, adjustment for aligning the beam spot 76 in a predetermined direction on the photosensitive member 68 can be performed in advance (before shipment to the market).
[0078]
In addition, the position data Y₂, Y_Three, Y_FourData t related to the light emission timing calculated based on₂, T_Three, T_FourSince the light source unit 19 itself includes the EEPROM 34 stored in advance, it is possible to replace only the light source unit 19 without making adjustments in the market for aligning the beam spot 76 in a predetermined direction on the photosensitive member 68. The labor and cost required for replacing the laser diode 36 can be greatly reduced.
[0079]
Further, since light is emitted based on the data stored in advance as described above, the design of the scanning optical system in which the light source unit 19 is used or the light source unit 19 itself does not limit the light emission timing, and the degree of freedom in design. Can be increased.
[0080]
On the other hand, the light emission timing data (or position data) obtained by the above process and stored in the EEPROM 34 is, as shown in FIGS. 5 and 6, as a barcode label 78 having a barcode symbol obtained by barcode-coding the data. The light source unit 19 is attached.
[0081]
The bar code label 78 includes numerical data obtained by digitizing the light emission timing data (or position data) in addition to the bar code symbol. When the light source unit 19 is replaced due to wear in the market after shipment, The user can check the positional deviation visually.
[0082]
FIG. 20 is a block diagram relating to deviation control of the respective light emitting points 57a to 57d using bar code symbols, and FIG. 21 is a flowchart of the storing process of the EEPROM 34.
[0083]
In FIG. 20, the EEPROM 34 can store the light emission timing data obtained in the above-described light emission timing data calculation step according to various conditions (routes).
[0084]
The conditions at this time include the production process of the light source unit 19 (after step 10 in FIG. 21), the production process of the image forming apparatus (after step 20 in FIG. 21), the time of market installation, confirmation of maintenance, etc. It can be considered when the unit 19 is consumed (step 30 and after in FIG. 21). Further, as a storage route, direct writing immediately after the calculation process at the time of production of the light source unit 19, input from a reading device (bar code reader) 79 for reading a bar code symbol, 10 keys 80 of an operation panel existing in the image forming apparatus. Input from the communication terminal, communication input from the communication terminal (or server) 81, and the like.
[0085]
The light emission timing data stored in the EEPROM 34 is output to the CPU 33 when the image forming apparatus is activated. The CPU 33 emits light while controlling the light emission timings of the light emission points 57a to 57d of the multi-beam laser diode 36 based on the light emission timing data. The data stored in the EEPROM 34 can be used as position data, and the CPU 33 can control the light emission by calculating the light emission timing data based on the position data.
[0086]
Next, the storage route in each process will be described.
[0087]
(Step 10)
In step 10, in the process of producing the light source unit 19, the base member 35 and the circuit board 32 are assembled to the mounting bracket 20, the light source unit 19 is assembled, and the process proceeds to step 11.
[0088]
(Step 11)
Data is stored in the EEPROM 34 through the position data acquisition process and the light emission timing data calculation / storage process described above (may be performed in Step 22 described later), and the process proceeds to Step 12.
[0089]
(Step 12)
In step 12, a barcode label 78 having a barcode symbol obtained by barcode-coding the data and the digitized numeric data based on the light emission timing data obtained in step 11 is created, and then the barcode label 78 is used as a light source. Affix to unit 19. From this state, for example, when the light source unit 19 is assembled in the production process of the image forming apparatus, the process proceeds to step 21, and when the light source unit 19 is assembled as a replacement part due to wear or the like to the image forming apparatus on the market, the step is performed. Move to 30.
[0090]
(Step 20)
In step 20, the image forming apparatus such as the housing 60 and the photosensitive member 68 is assembled, and the process proceeds to step 21 in a predetermined process.
[0091]
(Step 21)
In step 21, the light source unit 19 is assembled in the housing 60 and the process proceeds to step 22.
[0092]
(Step 22)
In step 22, at least when the assembly (including the power supply system) related to the scanning optical system is completed, the light emission timing data obtained through the position data acquisition process and the light emission timing data calculation / storage process is stored in the EEPROM 34, and the process proceeds to step 23. And migrate. As a method of storing the light emission timing data in the EEPROM 34, the barcode label 78 is read by using the 10-key of the image forming apparatus in addition to reading the barcode symbol 78 of the barcode label 78 by the barcode reading device and writing to the EEPROM 34. The writing to the EEPROM 34 by inputting the numerical data is considered, or the writing to the EEPROM 34 using the network RAN in the image forming apparatus production factory is conceivable.
[0093]
(Step 23)
In step 23, after a test at the time of shipment of the image forming apparatus or after market sales, light emission timing data is output from the EEPROM 34 to the CPU 33 with the main power supply of the image forming apparatus being turned on as a trigger, and the light emission points 57a to 57d emit light. Control is made.
[0094]
(Step 30)
In step 30, when 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 judgment such as generation of a failure error signal, the light source unit 19 has been assembled in the housing 60 until now. After the light source unit 19 is removed, a new light source unit 19 is incorporated in the housing 60 and the process proceeds to step 31.
[0095]
(Step 31)
In step 31, after the confirmation of incorporation, for example, the numerical data written together with the barcode symbol on the barcode label 78 is artificially read, and the numerical data is inputted from the 10 key 80 of the image forming apparatus. New light emission timing data is output to the EEPROM 34, and the routine proceeds to step 22.
[0096]
Although specific embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments.
[0097]
For example, the arrangement direction Q of the light emitting points 57a to 57d_FourA virtual straight line L (see FIG. 9)₂After rotating the multi-beam laser diode 36 once so as to align with the extending direction of, the virtual straight line L of the remaining light emitting points 57a to 57d₂The above-described adjustment may be performed so as to correct the deviation.
[0098]
Further, for example, the CPU 33 as the control means is provided in the housing 60 of the image forming apparatus separately from the light source unit 19, and the EEPROM 34 as the storage means is provided in the housing 60 of the image forming apparatus separately from the light source unit 19, The barcode label 78 may be provided on the housing 60 of the image forming apparatus separately from the light source unit 19 (see FIG. 10), or the CPU 33, the EEPROM 34, and the barcode label 78 may be provided in combination on the light source unit 19 or the housing 60. good.
[0099]
At this time, for example, when only the barcode label 78 is provided in the light source unit 19 and the CPU 33 and the EEPROM 34 are provided in the housing 60, the existing control means and storage means in the image forming apparatus can be used as the CPU 33 and the EEPROM 34. Reduction of parts cost can be realized.
[0100]
Further, when the CPU 33 and the bar code label 78 are 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 as an existing storage means provided in an operation panel or the like of the image forming apparatus. For example, when the image forming apparatus is connected to a telecommunication line (including a network line such as a RAN in a production factory) as in the case where the image forming apparatus is a facsimile, the line is used to connect to the EEPROM 34. It is possible to change the position data and the light emission timing data for the storage means on the image forming apparatus main body side.
[0101]
Of course, when the CPU 33 and the EEPROM 34 described above are disconnected from the light source unit 19, the electrical connection with the light source unit 19 is made and controlled.
[0102]
【The invention's effect】
As described above, in the light source unit according to claim 1, when the multi-beam laser diode and the optical lens are installed in the scanning optical system, the beam spots of the plurality of laser beams that pass through the optical lens are predetermined. By emitting light based on position data corresponding to the deviation from the virtual straight line of each light emitting point stored in advance so as to scan the recording medium while being aligned in the direction, the deviation of each light emitting point from the virtual straight line is reduced. Since each light emitting point emits light based on the corresponding position data, the adjustment device for obtaining the position data can be less expensive than the adjustment device in the case of detecting a time shift of the ns order. Since it is stored in advance, adjustment for aligning the beam spots in a predetermined direction on the recording medium can be performed in advance. Since light is emitted based on the data stored in advance as described above, the design of the scanning optical system in which the light source unit is used or the light source unit itself does not limit the light emission timing, and the degree of freedom in design is increased. be able to.
[0103]
The light source unit according to claim 2, further comprising storage means for storing in advance light emission timing data corresponding to the light emission timing of each light emitting point calculated based on the position data or the position data. The light emission of each light emitting point is controlled based on any data stored in the above.
[0104]
The gist of the light source unit according to claim 3 is provided with control means for controlling light emission at each of the light emitting points based on any data stored in the storage means.
[0105]
The light source unit according to claim 4 includes a barcode label obtained by barcode-coding either the position data or the light emission timing data.
[0106]
In the light source unit according to claim 5, the bar code label is written together with numerical data obtained by digitizing either the position data or the light emission timing data.
[0107]
According to the light source unit according to any one of claims 2 to 5, the light source unit itself includes storage means in which light emission timing data corresponding to the light emission timing calculated based on the position data or the position data is stored in advance. This makes it possible to replace only the light source unit without making adjustments in the market to align the beam spots in a predetermined direction on the recording medium, greatly reducing the labor and cost required to replace the multi-beam laser diode. Can do.
[0108]
The image forming apparatus according to a sixth aspect includes the light source unit according to any one of the first to fifth aspects.
[0109]
The image forming apparatus according to claim 7, comprising the light source unit according to claim 1, and a light emission timing corresponding to the position data or a light emission timing of each light emitting point calculated based on the position data. Storage means storing data in advance is provided separately from the light source unit, and the light emission of each light emitting point is controlled based on any data stored in the storage means.
[0110]
The image forming apparatus according to claim 8, comprising the light source unit according to claim 1, and a light emission timing corresponding to the position data or a light emission timing of each light emitting point calculated based on the position data. A storage unit that stores data in advance is provided separately from the light source unit, and a control unit that controls the light emission of each light emitting point based on any data stored in the storage unit is provided integrally with the light source unit. ing.
[0111]
The image forming apparatus according to claim 9, comprising the light source unit according to claim 1, and a light emission timing corresponding to the position data or a light emission timing of each light emitting point calculated based on the position data. A storage unit that stores data in advance and a control unit that controls the light emission of each light emitting point based on any data stored in the storage unit are provided separately from the light source unit.
[0112]
The image forming apparatus according to claim 10 has the light source unit according to claim 2 and controls the light emission of each light emitting point based on any data stored in the storage means. Are provided separately from the light source unit.
[0113]
The image forming apparatus according to claim 11, wherein a barcode label having a barcode symbol obtained by barcode-coding either the position data or the light emission timing data is integrated with or separate from the light source unit. Prepare.
[0114]
In the image forming apparatus according to claim 12, numerical data obtained by digitizing either the position data or the light emission timing data is written together in the barcode label.
[0115]
According to a thirteenth aspect of the present invention, the image forming apparatus includes an input unit that reads the bar code symbol with a reading device and inputs a result read by the reading device into the storage unit.
[0116]
The image forming apparatus according to claim 14 includes an input unit that inputs the numerical data to the storage unit.
[0117]
The image forming apparatus according to claim 15, wherein the input unit is a telecommunication line.
[0118]
The image forming apparatus according to claim 16, wherein the input means is a numeric key provided on the image forming apparatus main body.
[0119]
In the image forming apparatus according to claim 17, the light source unit is detachable.
[0120]
According to the image forming apparatus of the sixth aspect to the seventeenth aspect, the effect of any one of the first aspect to the fifth aspect can be enjoyed in the image forming apparatus.
[0121]
19. The method of producing a light source unit according to claim 18, wherein a plurality of laser beams transmitted through the optical lens are projected onto the light receiving element to obtain position data corresponding to the deviation of each light emitting point from the virtual straight line. An acquisition step, and a storage step of storing the position data obtained in the position data acquisition step in the storage means.
[0122]
20. The method of producing a light source unit according to claim 19, wherein a plurality of laser beams transmitted through the optical lens are projected onto the light receiving element to obtain position data corresponding to the deviation of each light emitting point from the virtual straight line. Each emission point based on the acquisition process and the position data so that when the light source unit is installed in the scanning optical system, the beam spot of a plurality of laser beams that pass through the optical lens is scanned in a predetermined direction while being scanned on the recording medium. A light emission timing data calculation step for calculating light emission timing data relating to the light emission timing, and a storage step for storing the light emission timing data obtained in the light emission timing data calculation step in a storage means.
[0123]
21. The method for producing a light source unit according to claim 20, wherein the barcode label has a barcode symbol that is barcoded corresponding to the data obtained in either the position data acquisition step or the light emission timing data calculation step. A label creating process for creating a label, a pasting process for pasting a barcode label to a light source unit or an image forming apparatus, and a bar code symbol pasted in the pasting process by reading the bar code symbol in the storing process. Data or light emission timing data is stored.
[0124]
According to the method for producing the light source unit according to any one of claims 18 to 20, the position data corresponding to the deviation of each light emitting point from the virtual straight line when performing adjustment for aligning the beam spot in a predetermined direction on the recording medium. Therefore, the adjustment device is less expensive than the case of detecting a time shift in the order of ns, and data relating to the light emission timing calculated based on the position data is stored in the storage means. It can be completed in advance (before shipment of the light source unit 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, the design of the scanning optical system in which the light source unit is used or the light source unit itself has a limitation on the light emission timing. Therefore, the degree of freedom in 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;
4 is a plan view showing the mounting bracket of FIG. 1. FIG.
FIG. 5 is an exploded perspective view showing the base member of FIG. 1 in an enlarged manner.
6 is an exploded perspective view showing a state in which the base member of FIG. 5 is viewed from the back side.
7 is a front view showing a state in which the light source unit of FIG. 1 is assembled. FIG.
8 is a rear view showing a state in which the light source unit of FIG. 1 is assembled. FIG.
FIG. 9 is an explanatory view showing an enlarged view of the multi-beam laser diode of FIG. 1;
FIG. 10 is an explanatory view showing a housing before a light source unit is attached.
FIG. 11 is an explanatory view showing a housing to which a light source unit is attached.
FIG. 12 is an explanatory diagram showing an adjustment device.
13 is an explanatory diagram showing an optical arrangement of the adjusting device in FIG. 12. FIG.
14 is an explanatory diagram showing beam spots on the imaging surface of the adjustment apparatus of FIG. 12. 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 centroid position from a beam intensity distribution curve.
FIG. 17 is an explanatory diagram showing a relationship between the diameter of a beam spot and the size of an imaging surface.
FIG. 18 is an explanatory diagram showing the relationship between the number of light emitting points during light emission and the laser beam output.
FIG. 19 is an explanatory diagram showing beam spots on the photoreceptor of the image forming apparatus.
FIG. 20 is a block diagram relating to deviation control of light emitting points using bar code symbols.
FIG. 21 is a flowchart of a data storing process in a storing unit.
FIG. 22 is an explanatory diagram showing a schematic configuration of a conventional scanning optical system.
23 is an explanatory diagram showing beam spots on the surface of the photosensitive member of the scanning optical system of FIG.
24 is an enlarged front view showing the multi-beam laser diode of FIG.
25 is an explanatory diagram showing a deviation between the direction in which the virtual line extends in the multi-beam laser diode of FIG. 24 and the arrangement direction of a plurality of light emitting points.
[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: luminous point
57b ... luminous point
57c ... luminous point
57d: luminous point
58 ... Notch
60 ... Housing
68 ... Photoconductor (recording medium)
76 ... Beam spot
78 ... Barcode label
L ... Virtual straight line

Claims (20)

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 the stem, and an optical lens that converts the plurality of laser beams emitted from the light emitting points into parallel light beams A light source unit for a scanning optical system,
When the multi-beam laser diode and the optical lens are installed in the scanning optical system, beam spots of a plurality of laser beams that pass through the optical lens are stored in advance so as to scan the recording medium while being aligned in a predetermined direction. Further, the light source unit emits light based on position data corresponding to a deviation of each light emitting point from the virtual straight line. Storage means for storing in advance light emission timing data corresponding to the light emission timing of each light emitting point calculated based on the position data or the position data is provided, and each light emission based on any data stored in the storage means The light source unit according to claim 1, wherein the light emission of the point is controlled. The light source unit according to claim 2, further comprising a control unit that controls light emission of each of the light emission points based on any data stored in the storage unit. 4. The light source unit according to claim 2, further comprising: a bar code label obtained by bar-coding either the position data or the light emission timing data. 5. 5. The light source unit according to claim 4, wherein the bar code label is also written with 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. The light source unit according to claim 1, and a storage unit that stores in advance the light emission timing data corresponding to the light emission timing of each of the light emission points calculated based on the position data or the position data, separately from the light source unit. An image forming apparatus, characterized in that the light emission of each light emitting point is controlled based on any data stored in the storage means. The light source unit according to claim 1, and a storage unit that stores in advance the light emission timing data corresponding to the light emission timing of each of the light emission points calculated based on the position data or the position data, separately from the light source unit. An image forming apparatus comprising a control unit for controlling light emission at each of the light emitting points based on any data stored in the storage unit and integrally provided in the light source unit. The light source unit according to claim 1, wherein the position data or light emission timing data corresponding to the light emission timing of each light emission point calculated based on the position data is stored in advance and stored in the storage means. An image forming apparatus comprising: a control unit that controls light emission at each of the light emission points based on any data, separately from the light source unit. The light source unit according to claim 2, and a control unit that controls light emission of each light emitting point based on any data stored in the storage unit, separately from the light source unit. Image forming apparatus. 11. The barcode label having a barcode symbol obtained by barcode-coding either the position data or the light emission timing data is provided integrally with or separately from the light source unit. The image forming apparatus according to any one of the above. The image forming apparatus according to claim 11, wherein the bar code label is accompanied by numerical data obtained by digitizing either the position data or the light emission timing data. The image forming apparatus according to claim 11, further comprising: an input unit that reads the barcode symbol by a reading device and inputs a result read by the reading device to the storage unit. The image forming apparatus according to claim 12, further comprising an input unit that inputs the numerical data to the storage unit. The image forming apparatus according to claim 13, wherein the input unit is a telecommunication line. The image forming apparatus according to claim 14, wherein the input unit is a numeric key provided on a main body of the image forming apparatus. The image forming apparatus according to claim 7, wherein the light source unit is detachable. 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 the stem, and an optical lens that converts the plurality of laser beams emitted from the light-emitting points into parallel light beams Comprising a light source unit that emits light in accordance with an output signal of the control means.
A position data acquisition step of projecting a plurality of laser beams transmitted through the optical lens onto a light receiving element to obtain position data corresponding to the deviation of each light emitting point from the virtual line;
And a storage step of storing in the storage means the position data obtained in the position data acquisition step. 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 the stem, and an optical lens that converts the plurality of laser beams emitted from the light-emitting points into parallel light beams Comprising a light source unit that emits light in accordance with an output signal of the control means.
A position data acquisition step of projecting a plurality of laser beams transmitted through the optical lens onto a light receiving element to obtain position data corresponding to the deviation of each light emitting point from the virtual line;
Each light emission based on the position data so that, when the light source unit is installed in a scanning optical system, a beam spot of a plurality of laser beams that pass through the optical lens is scanned on a recording medium while being aligned in a predetermined direction. A light emission timing data calculating step for calculating light emission timing data related to the light emission timing of the point;
And a storage step of storing the light emission timing data obtained in the light emission timing data calculation step in a storage means. A label creation step for creating a barcode label having a barcode symbol barcoded corresponding to the data obtained in either the position data acquisition step or the light emission timing data calculation step;
An attaching step of attaching the barcode label to the light source unit or the image forming apparatus;
The position data or the light emission timing data in the storage means in the storage step is stored by reading the barcode symbol pasted in the pasting step. A method for producing the image forming apparatus described above.

Images