JP3928475B2 - Reading apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a reading device for outputting an image signal to an original image is read by moving an optical system, relates it to the image forming equipment which integrally.
[0002]
[Prior art]
The reading device is generally composed of a document table, an illumination lamp and a pair of reflecting mirrors, and a moving optical system that scans the document surface and a photographing element such as a CCD that is provided on the imaging surface and reads an image. The image forming apparatus main body is assembled as a rectangular unit material separate from the image forming apparatus main body, and is then mounted substantially horizontally with respect to the upper surface of the image forming apparatus main body and fixedly attached at the four corners.
[0003]
[Problems to be solved by the invention]
For smooth operation of the moving optical system and accurate reading of an image, the reading device must be attached to the unit in a stable posture without any stress or deformation caused by stress when it is fixed to the image forming apparatus main body.
[0004]
However, the main body of the image forming apparatus has poor flatness on the top surface or may be deformed due to the influence of the floor to be installed even if the flatness is good. Attention is paid to the mounting work so that distortion is not transmitted to the reading unit due to adjustment or the like. However, even if attention was paid, it was not always satisfied.
[0005]
As a result of solving this problem and improving the present invention, the reading apparatus is supported and attached to the image forming apparatus main body by three-point receiving in consideration of mass balance, so that the unit is not deformed and smooth. is intended to provide an image forming apparatus is ensured an image formation of high quality by mounting the can reader before Symbol reader accurate image reading by the operation of the optical system.
[0006]
[Means for Solving the Problems]
The above purpose is
The reading device is a three-point receiver, and the three-point receiving position is selected so that the geometric center-of-gravity position with respect to the three-point receiving position is within a predetermined interval with respect to the center-of-gravity position of the reading device. A reading device fixed to the upper part of the image forming apparatus main body ,
When the predetermined interval is L _G and the distances to the geometric center of gravity with respect to the three-point receiving position are L _A , L _B , and L _C , respectively ,
L _G ≦ {(L _A + L _B + L _C ) / 3} × 0.15
And having a relationship
When the projected area of the reading device is S and the area of a triangle formed by the three-point receiving position is S ₀ ,
S ₀ ≧ (1/2) S
Reader and having a relationship of (the invention of claim 1), and using a reading device according to claim 1, the read document information to form an image by performing scanning exposure on the photoreceptor An image forming apparatus characterized in that (Invention of claim 3 )
Achieved by:
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Prior to the description of the present embodiment, the structure and operation of an image forming apparatus according to the present invention will be described with reference to FIG.
[0008]
The apparatus includes a document image reading unit 10, a laser writing unit 20, an image forming unit 30, and a paper feeding unit 40.
[0009]
The document image reading unit 10 is configured as an independent reading device 50 separate from the apparatus main body, and is placed and fixed on the upper surface of the apparatus main body.
[0010]
The reading device 50 includes an original platen 51 made of a transparent glass plate and the like on the upper side, and an original cover 52 that covers the original D placed on the original platen 51, and a first mirror unit below the original platen 51. 12, an image reading unit 10 including a second mirror unit 13, a main lens 14, an image pickup device 15 such as a CCD array, and the like is provided. The first mirror unit 12 includes an illumination lamp 12A and a first mirror 12B. The first mirror unit 12 is mounted in parallel with the document table 51 and linearly movable in the horizontal direction of the drawing, and optically scans the entire surface of the document D. The second mirror unit 13 is integrally provided with a second mirror 13A and a third mirror 13B, and moves linearly in the left-right direction at a speed half that of the first mirror unit 12 so as to always maintain a predetermined optical path length. Of course, the movement of the second mirror unit 13 is parallel to the document table in the same manner as the first mirror unit 12. The image of the document D on the document table 51 illuminated by the illumination lamp 12A is formed on the image sensor 15 by the main lens 14 via the first mirror 12B, the second mirror 13A, and the third mirror 13B. It has become. When the scanning is finished, the first mirror unit 12 and the second mirror unit 13 return to their original positions and wait until the next image formation.
[0011]
The image data obtained by the image sensor 15 is processed by an image signal processing unit (not shown) and temporarily stored in the memory as an image signal. Next, the image signal is input to the laser writing unit 20.
[0012]
In the laser writing unit 20, the image signal from the memory is controlled by the control unit so that the laser writing including the drive motor 21, the polygon mirror 22, the fθ lens 23, the mirrors 24, 24, and 26, a semiconductor laser (not shown), a correction lens, and the like. When input to the unit 20, the image recording operation is started. Next, in the image forming unit 30, the photosensitive drum 31 as an image carrier rotates clockwise as indicated by an arrow and is discharged by a charge eliminator 36 that performs charge pre-exposure to remove charges, and then discharge wires 32A, Since the electric charge is given by the charger 32 having the charging grid 32 </ b> B, an electrostatic latent image corresponding to the image of the document D is formed on the photosensitive drum 31 by the laser beam L from the laser writing unit 20. Thereafter, the electrostatic latent image on the photosensitive drum 31 is reversely developed by a developer carried by the developing sleeve 33A to which a bias voltage in which an AC component is superimposed on a DC component of the developing device 33 is applied, and is visible. It becomes a toner image.
[0013]
On the other hand, the transfer paper P having a specified size is carried out one by one by the carry-out roller 42A from the paper feed cassette 41A or 41B loaded in the paper feed unit 40, and the image transfer unit is passed through the carry-out roller 43 and the guide member 42. Feed the paper toward. The fed transfer paper P is sent onto the photosensitive drum 31 by a registration roller 44 that operates in synchronization with the toner image on the photosensitive drum 31. A toner image on the photosensitive drum 31 is transferred to the transfer paper P by the action of the transfer device 34, and is separated from the photosensitive drum 31 by the charge eliminating action of the separator 35, and then fixed via the conveying belt 45. The sheet is sent to a container 37 and melted and fixed by a heating roller 37A and a pressure roller 37B, and then discharged to a tray outside the apparatus by discharge rollers 38 and 46.
[0014]
The photosensitive drum 31 continues to rotate, and the toner remaining without being transferred to the surface of the photosensitive drum 31 is removed and cleaned by the cleaning blade 39A pressed against the cleaning device 39, and then the charge is removed again by the charge eliminator 36. The charge is applied uniformly by 32, and the next image forming process is started.
[0015]
The reading device 50 has a long rectangular shape in the scanning direction (arrow) of the optical system as shown in the perspective view of FIG. A total of three points, points A and B near both ends of the side, and point C at the substantially central part of the long side on the front side, are placed and fixed on the upper surface of the image forming apparatus main body.
[0016]
The three-point receiving position of the reading device 50 is selected and determined so as to satisfy the following conditions.
[0017]
(1) As a first condition, as shown in FIG. 3, the geometric gravity center position G _{0 of} the triangle formed by the points A, B, and C is not far from the gravity center position G of the reading device 50. restricts such, each point a, B, including C and the center of gravity G ₀ the connecting length L _a, L _B, L _C and the center of gravity G ₀ and the distance L _G between G is the experience obtained by experiment It is desirable to be within the range indicated by the following conditional expression.
[0018]
L _G ≦ {(L _A + L _B + L _C ) / 3} × 0.15
When deviating from the above range, there is a lack of safety and distortion may occur.
[0019]
(Example) The center of gravity position of the reading device 50 shown in FIG. 3 is obtained by actual measurement, and the obtained center of gravity position is entered on the plan view of the reading device 50, and is attached at the peripheral portion of the reading device 50 on the plan view. The three-point receiving positions A, B, and C that are made possible are selected, the geometric gravity center position G ₀ of the selected triangle ABC is obtained, and it is checked whether or not the above conditional expression is satisfied. In the present embodiment, the above conditional expression is satisfied.
[0020]
L _A = 380.5 mm, L _B = 347.4 mm, L _C = 294.4 mm
L _G = 38.2 mm (boundary dimension value 51.1 mm or less)
The three-point receiving positions A, B, and C having the dimensional relationship are obtained, and the reading device 50 is attached and fixed to the actual machine. As a result, the reading device 50 can maintain a stable reading operation without being affected by vibration during transportation, fluctuations in temperature and humidity, and the like.
[0021]
The receiving positions A, B, and C of the reading device 50 shown in FIG. 4 are examples selected on the short side of the reading device 50, and this embodiment also satisfies the above conditional expression.
[0022]
L _A = 502.9 mm, L _B = 298.7 mm, L _C = 301.0 mm
L _G = 51.8 mm (boundary dimension value 55.1 mm or less)
Is fixed.
[0023]
(2) As a second condition, it is preferable that the area S _{0 of} the triangle formed by each of the points A, B, and C is at least half or more than the projected area S of the reading device 50. When the first condition is satisfied, the reading device 50 is placed on the image forming apparatus main body in a stable state with good balance. By maintaining this relationship, even if pressure is applied to the upper surface corner of the reading device 50, excessive stress is not generated inside.
[0024]
If the above-mentioned triangular area S ₀ can secure a half or more of the projected area S of the reading device 50, the three-point receiving position can be obtained as shown in FIG. It is also possible to select C on the short side of the reading device 50.
[0025]
(Example) In the reading apparatus 50 shown in FIG. 3, with respect to the projection area S = 2810 cm ² , the triangular area S ₀ = 2288 cm ² formed by the three-point receiving positions A, B, C and S ₀ ≧ (1 / 2) The condition of S is satisfied. In this embodiment, since the conditional expression (1) is satisfied and the condition (2) is also satisfied, even if pressure is applied to the top corner of the reading device 50, excessive stress is generated inside. Thus, extremely stable mounting and fixing can be performed.
[0026]
In the reading device 50 shown in FIG. 4, with respect to the projection area S = 2810 cm ² , the triangular area S = 1232 cm ² formed by the three-point receiving positions A, B, C and S ₀ ≧ (1/2) S. The condition is not met. This embodiment shows that the two receiving positions B and C provided on one short side of the reading device 50 need to be set with an interval as much as possible.
[0027]
FIG. 5 shows the relationship between each condition and the vibration acceleration at the center of the mirror of the first mirror operating at full rate. Usually, the limit value determined from the subjective evaluation viewed from the vibration acceleration image of the first mirror is 0.1G. If both the conditions 1 and 2 are satisfied, there is no problem, but if the condition 2 is not satisfied, a stable reading operation cannot be guaranteed. When the condition 1 is not satisfied, the read image is further deteriorated.
[0028]
(3) In the above-described three-point receiving position, the reading position 50 is fixed and integrated with the image forming apparatus main body via an attachment unit described below.
[0029]
In the reading device 50, an L-shaped attachment member 53 as shown in FIG. 7A is integrated with the side surface corresponding to the three-point receiving position, while the image forming apparatus main body corresponds to the attachment member 53. An elastic support member 54 is provided on the upper surface.
[0030]
The support member 54 is configured to fix the mounting member 53 by pressing the hard rubber 54C by means of bolts 54A and nuts 54B, and the reading device 50 is made of the hard rubber 54C in a state of slightly floating above the upper surface of the image forming apparatus. Elastically supported by pressure. As a result, the reading device 50 is free from deformation and breakage, distortion received from the image forming apparatus main body, etc., and when an excessive external force is applied, it is absorbed and fixed in a normal state.
[0031]
The reading device 50 is specified in at least two corners E and F other than the three-point receiving positions A, B, and C as shown in FIG. 6 together with fixing at the three-point receiving positions A, B, and C. The receiving member is attached to prevent deformation and breakage due to external force.
[0032]
As the receiving members in E and F, an attachment member 53A attached through a long hole 153A according to the height of the reading device 50 as shown in FIG. 7B, and an image formation as shown in FIG. 7C. An attachment member 53B that comes into contact with the upper surface of the main body of the apparatus with an appropriate elasticity of the elastic member 153B, and is further attached to the upper surface of the main body of the image forming apparatus as shown in FIG. Any one of the attachment members 53C or the like is used.
[0033]
Note that the reading device 50 has the above-described three-point receiving position in consideration of the fact that the gravity center position G varies in the scanning direction due to the movement of the first and second mirror units 12 and 13 in the image reading unit 10. If C is provided in the form of being divided into two parts separated by a small distance in consideration of the movement of the center of gravity as shown in FIG. 8, the reading device 50 is supported and fixed in a more stable state.
[0034]
In addition, since the flatness of the reading device mounting surface of the image forming apparatus is determined by four points when the conventional four-point fixing is used, the distortion of the image forming apparatus is reflected as it is. In the case of FIG. 8, it is possible to mount the reading device while reducing the distortion of the image forming apparatus.
[0035]
Even in the case of a pseudo three-point bearing as shown in FIG. 8 considering the movement of the center of gravity, the distance between the mounting members 53 in FIG. Since the distance is remarkably reduced, it is sufficient to make the structure difficult to receive the distortion of the image forming apparatus.
[0036]
Normally, it is possible to obtain a good reading operation by setting the interval C to 1/3 to 1/5 with respect to the interval E-F in FIG.
[0037]
【The invention's effect】
The present invention, units of the image reading apparatus Ri that Do and is placing the tower firmly and stably in the image forming apparatus body without causing any distortion or deformation caused by mounting, even more damage due to an external force after installation prevention It was to be done.
[0038]
The function of the time of assembly even after installation of the unit is an image forming apparatus of the image reading apparatus, the performance is maintained, the result always possible reading device reading the high-quality image is provided, therefore always high quality An image forming apparatus for forming an image has been realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating the structure of a reading device and an image forming apparatus according to the present invention.
FIG. 2 is a perspective view illustrating a method for fixing a reading device.
FIG. 3 is an explanatory diagram illustrating a relationship between a gravity center position and a fixed position of a reading device.
FIG. 4 is an explanatory diagram showing a relationship between a gravity center position and a fixed position of another reading apparatus.
FIG. 5 is a diagram showing a relationship between each condition and vibration acceleration of the first mirror.
FIG. 6 is a perspective view illustrating a fixing example of a reading device.
FIG. 7 is a main part view showing fixing means of the reading apparatus.
FIG. 8 is a perspective view illustrating a fixing example of another reading device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Reading part 12 1st mirror unit 13 2nd mirror unit 14 Main lens 15 Image pick-up element 20 Laser writing part 30 Image forming part 40 Paper feed part 50 Reading device 53, 53A, 53B, 53C Mounting member 54 Support member 54A Bolt 54B Nut 54C Hard rubber A, B, C Three-point receiving position D Original E, F Corner G, G ₀ Center of gravity P Transfer sheet S, S ₀ area H (Allowable) Elastic deformation amount

Claims (3)

The reading device is a three-point receiver, and the three-point receiving position is selected so that the geometric center-of-gravity position with respect to the three-point receiving position is within a predetermined interval with respect to the center-of-gravity position of the reading device. A reading device fixed to the upper part of the image forming apparatus main body ,
When the predetermined interval is L _G , and the distances from the three-point receiving positions to the geometric center of gravity are L _A , L _B , and L _C , respectively ,
L _G ≦ {(L _A + L _B + L _C ) / 3} × 0.15
And having a relationship
When the projected area of the reading device is S and the area of a triangle formed by the three-point receiving position is S ₀ ,
S ₀ ≧ (1/2) S
A reader having the following relationship: The reading apparatus according to claim 1, wherein the reading apparatus is supported at two or more locations while being fixed at the three-point receiving position. An image forming apparatus using the reading apparatus according to claim 1 to form an image by performing scanning exposure on a photoconductor on the basis of the read document information.

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