JP3472070B2 - Image processing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus such as a scanner, a copying machine, or a facsimile which has a function of reading an image of an original while moving an original table on which the original is set.

[0002]

2. Description of the Related Art In a conventional image processing apparatus, for the purpose of downsizing and simplification of the apparatus, for example, a so-called manuscript table moving type copying machine for performing a copying operation by moving a manuscript table on which a manuscript is set to the left and right. There is.

The original table moving type copying machine shown in FIG. 6 is constructed such that the original table 51 moves to the left and right during a copying operation, and the image of the original set on the original table 51 is copied onto recording paper. .

As shown in FIG. 7, the structure of the document table portion is as follows.
A pressure plate 52 for covering the document, a document table glass 53 on which the document is placed, a rack table 54 for holding the document table glass 53, the copying machine body and the rack table 54 are combined, and the rack table 54 can be freely moved in the horizontal direction. Slide rails 55 and rack base 54 to keep them moving
And a rack gear 56 for moving the document table 51 to the left and right in response to a driving force from a pinion gear (not shown) attached to the main body of the copying machine.

[0005]

However, in the above conventional rack and pinion system manuscript table moving type copying machine, since the rack table 54 and the rack gear 56 are respectively configured as separate parts, the rack table 54 is not provided. When the rack gear 56 is attached to the rack gear 56, the tooth surface of the rack gear 56 may be damaged, and there is a risk that the rack gear 56 cannot be used. Further, since the rack base 54 and the rack gear 56 are configured as separate parts, it is also disadvantageous in terms of dimensional accuracy.

On the other hand, it is difficult to maintain proper engagement between the rack gear 56 and the pinion gear (not shown) at all times, and as a result, the document table 51 vibrates due to backlash between the gears, and copying is performed. It was a cause of image blurring. 8 and 9 schematically show how the conventional rack gear 56 and pinion gear 57 mesh with each other. FIG. 8 is a cross-sectional view of the platen drive mechanism seen from the front, and FIG. 9 is a moving direction of the platen. FIG. 3 is a cross-sectional view of a document table drive mechanism portion viewed from above. In FIGS. 8 and 9, 58 is a pinion gear.
57 rotation support shaft.

In FIG. 8, the rack gear 56 and the pinion gear 57 are meshed with each other with pitch lines 56p and pitch circles 57p having an appropriate gap a. Therefore, if the value of the gap a changes due to factors such as the dimensional tolerances of the rack gear 56 and the pinion gear 57 and the positional deviation of the rotary support shaft 58, the meshing state of the two changes, and the document table 51 vibrates and copies. There was a problem that the image deteriorates.

Further, temporarily, the rack gear 56 and the pinion gear 57
Even if the original table 51 is properly meshed with the original table 51, when the original table 51 reaches the left and right end positions, the original table 51 tilts like a seesaw due to the weight of the original table glass and the like. . Due to this inclination, the rack gear 56 and the pinion gear 57 change into a meshed state (backlash, etc.).
Then, vibration occurred and as a result, the copied image was blurred and the image quality was deteriorated.

Therefore, an object of the present invention is to reduce the risk of damaging the tooth surface of the rack gear at the time of assembly, and to prevent image blurring due to a change in the meshing state of the rack gear and the pinion gear (backlash etc.). To do.

[0010]

A typical configuration of the present invention for achieving the above object is an image processing apparatus having a function of reading an image of a document while moving a document table on which the document is set. A holding member for holding the document table,
A rack gear provided on the holding member in parallel with the moving direction of the document table, a first abutting member provided in parallel with the rack gear, a pinion gear for meshing with the rack gear to move the document table, and the pinion. A second abutting member that rotates integrally with the gear and abuts on the first abutting member to hold the rack gear at a predetermined position with respect to the pinion gear;
The rack gear and the first butting member are integrally formed, and the rack gear and the first butting member are elastically supported with respect to the holding member.

Specifically, for example, a slit is provided in the vicinity of the rack gear integrally formed with the holding member and the first abutting member in parallel with the moving direction of the document table.

According to the above construction, since the rack gear is formed integrally with the holding member, it is possible to reduce the risk of scratching the tooth surface of the rack gear due to a work mistake during assembly. Further, since the rack gear is elastically supported with respect to the holding member by providing a slit in the vicinity of the rack gear, it is possible to prevent image blurring due to backlash between gears and to obtain a good image. Obtainable.

Further, a change amount in the height direction of the holding member caused by the inclination of the holding member due to the movement of the document table is δ, and a force required to bend the rack gear by the change amount δ is P, When the sectional moment of inertia of the rack gear calculated from the sectional shape of the rack gear is I and the Young's modulus of the material of the holding member is E, the length L of the slit is at least L = (192EIδ / P) By making it ^1/3 or more, even if the material of the member is changed,
By changing the length of the slit, the elasticity (flexibility) of the rack gear can be optimally adjusted.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an image processing apparatus to which the present invention is applied will be specifically described below with reference to the drawings.

[First Embodiment] An image processing apparatus according to the first embodiment will be described in detail with reference to the drawings. still,
In the present embodiment, as the image processing apparatus, a copying machine of a moving platen type will be described as an example.

First, a schematic structure of a copyboard moving type copying machine will be briefly described with reference to FIG. FIG. 4 is a schematic cross-sectional view showing the schematic configuration of a document table moving type copying machine to which the present invention is applied.

As shown in FIG. 4, in the manuscript table moving type copying machine, the manuscript table 1 moves to the left and right during the copying operation.
The image of the original G set on the recording sheet S is copied onto the recording sheet S.

The manuscript G set on the manuscript table 1 is moved by the manuscript table 1 in the direction of the arrow in FIG.
Is irradiated with light, and the reflected light (image light) is guided to the photoconductor drum 12 of the image forming unit. Around the photosensitive drum 12, a charging means 13, a developing means 14, a cleaning means 15 and the like as process means acting on the photosensitive drum 12 are arranged, and an image is formed by a known electrophotographic method. To be done. In the present embodiment, the above-mentioned members are integrated into a process cartridge 16, and the process cartridge 16 is configured to be attachable to and detachable from the apparatus main body.

On the other hand, the recording paper S set on the feeding tray 17 is fed to the image forming section by the feeding roller 18 and the conveying roller 19 at the same timing as the image forming operation of the image forming section. . Then, the image (toner image) formed on the photoconductor drum 12 is transferred onto the recording paper S by the transfer means 20, and after the transfer, the transferred image is fixed onto the recording paper S by the fixing means 21. After fixing, the recording paper S is discharged onto the discharge tray 23 by the discharge roller 22.

Next, the detailed structure of the document table portion in the copying machine will be described with reference to FIGS. Figure 1
2 is a perspective view showing the shape of a rack plate in the copying machine according to the present embodiment, FIG. 2 is a conceptual sectional view of the copying machine according to the present embodiment seen from the front, and FIG. 3 is a document table of the copying machine according to the present embodiment. FIG. 6 is a partial cross-sectional view of a drive mechanism portion as viewed from a moving direction of a document table.

In the figure, 2 is a pressure plate for covering a document (see FIG. 4), and 3 is a platen glass for placing a document (see FIG. 4).
4 is a rack plate as a holding member for holding the platen glass 3, 4b is a rack gear provided on the rack plate 4 in parallel with the moving direction of the platen 1 (direction of arrow in FIG. 4), and 4b.
a is a first abutting member provided in parallel with the rack gear 4b, 5 is a pinion gear that meshes with the rack gear 4b to move the document table 1, and 5a rotates integrally with the pinion gear 5 and One butting member 4
a in contact with the rack gear 4b and the pinion gear 5
A second butting member for holding it in place with respect to 6
Is a rotation support shaft of the pinion gear 5.

The rack plate 4, the rack gear 4b, and the first abutting member 4a are integrally formed, and the rack gear 4b and the first abutting member 4a are attached to the rack plate 4. It is configured to elastically support. Specifically, in this embodiment, two slits 4c are provided in the vicinity of the rack gear 4b integrally formed on the rack plate 4 and the first abutting member 4a in parallel with the moving direction of the document table 1. .

In the figure, the rack gear 4b and the pinion gear 5 are set so that their pitch lines 4p and pitch circles 5p mesh with each other with an appropriate gap a.

As shown in FIG. 2, when the rack plate 4 is at the center position of the main body (at the solid line in FIG. 2).
And when the distance from the exposure point is farthest during the copying operation (indicated by the one-dot chain line in FIG. 2), an inclination of δ occurs. Therefore, the first butting member 4a (hatched portion in FIG. 2) and the second butting member 5a are arranged in a position where they are overlapped by a height δ in advance, and the rack plate 4 is tilted during the copying operation. Also the first butting member 4a and the second butting member 5
The state in which a is in contact is maintained. For this reason,
During the copying operation, when the rack plate 4 is farthest from the exposure point, the rack gear portion is in a state of being straight with respect to the document table holding portion (indicated by the alternate long and short dash line in FIG. 2). The second butting member 5a pushes up the first butting member 4a, and the slits 4c provided on both sides of the rack gear bend the document holding portion (at the solid line in FIG. 2). become.

Further, as shown in FIG. 3, as described above,
During the copying operation, the first butting member 4a and the second butting member 5a are kept in contact with each other regardless of the position of the document table 1, and the pitch line 4p of the rack gear 4b and the pitch of the pinion gear 5 are kept. The state in which the circles 5p mesh with each other with an appropriate gap a is maintained. Therefore, even if the document table 1 moves during copying, vibration can be prevented.

As described above, since the rack gear 4b and the first abutting member 4a are integrally formed on the rack plate 4 for holding the document table 1 on which the document is set, the rack gear 4b is erroneous during assembly. You can reduce the risk of scratching the tooth surface. Further, since the slit 4c is provided near the rack gear to elastically support the rack gear 4b with respect to the rack plate 4, it is possible to prevent vibration of the document table 1 due to backlash between the gears. A good image with less blur can be obtained.

[Second Embodiment] An image processing apparatus according to the second embodiment will be described in detail with reference to FIG. Figure 5
FIG. 3 is a perspective view showing the shape of a rack plate in the copying machine according to the present embodiment.

In the present embodiment as well, the original table moving type copying machine is illustrated as the image processing apparatus, but the schematic configuration of the entire apparatus is the same as that of the above-described embodiment, and therefore the description thereof is omitted. Further, members having the same functions as those in the above-described embodiment are designated by the same reference numerals and the description thereof is omitted.

The rack plate 4 shown in FIG. 5A employs ABS (Young's modulus E = 2.058 × 10 ⁹ Pa) as a material. The second moment of inertia I of the rack portion is calculated from the width of the rack gear 4b of 9 mm and the height of 2.8 mm to I = 1.646.
× 10 ^-11 mm. Further, the inclination amount δ of the rack plate 4 is δ
= 0.8 mm, the force P required to bend the rack gear portion by 0.8 mm was set to P = 200 g so as not to apply an excessive load to the motor of the copying machine. At this time, the appropriate length L of the slit 4c is determined by the following mathematical formula in terms of material mechanics.

L = (192EI δ / P) ^1/3 ≈296 mm

In order to increase the strength of the rack gear tooth surface of the rack plate 4, the material is glass reinforced ABS (Young's modulus E = 5.68).
4 × 10 ⁹ Pa), the slit 4 as it is
With the length of c, the flexing of the rack portion is reduced by the increase of the Young's modulus E of the material, but the length L of the slit 4c is set to 416 mm from the above formula, and the ABS shown in FIG. A bend equivalent to that of a rack plate can be obtained (see FIG. 5 (b)).

As described above, according to the present embodiment, even if the material of the rack plate 4 is changed, the bending condition of the rack portion can be optimally adjusted by changing the length L of the slit 4c. That is, by changing the length L of the slit 4c, the bending degree of the rack portion can be arbitrarily changed, and optimization can be achieved according to the material of the rack plate 4.

[Other Embodiments] In the above-described embodiment,
As a structure for elastically supporting the rack gear on the holding member,
Although the configuration in which the slit is provided in the vicinity of the rack gear in parallel with the moving direction of the document table is illustrated, the present invention is not limited to this. Further, the number, length, shape, etc. of the slits may be appropriately determined so that the rack gear and the pinion gear can always be kept in an appropriate meshed state.

In the above-mentioned embodiment, the rack plate as the holding member is made of ABS or glass reinforced A.
Although BS is used, the material is not limited to this and other materials may be used.

Further, in the above-described embodiment, the copying machine adopting the electrophotographic system is exemplified as the image processing apparatus, but the image processing apparatus is not limited to this, and other image processing apparatuses such as a scanner and a facsimile may be used. Is also good. Further, the present invention is effective not only in the electrophotographic system but also in an image processing apparatus adopting another recording system such as an inkjet system.

[0036]

As described above, according to the present invention,
Since the holding member for holding the platen and the rack gear are integrally formed and the rack gear is elastically supported with respect to the holding member, more specifically, for example, a slit is formed near the rack gear integrally formed with the holding member. By providing the structure, it is possible to reduce the risk of damaging the tooth surface of the rack gear at the time of assembly, and it is also advantageous in terms of component accuracy.

Further, due to the function of the slit provided in the holding member, it is possible to prevent the vibration generated on the document table, the movement of the document table becomes smooth, and a good copy image with less blurring can be obtained. it can.

Further, by changing the length of the slit, the flexing condition of the rack can be arbitrarily changed, and the rack member can be optimized depending on the material of the holding member.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the shape of a rack plate in a copying machine according to a first embodiment.

FIG. 2 is a conceptual sectional view of the copying machine according to the first embodiment as viewed from the front.

FIG. 3 is a partial cross-sectional view of a document table driving mechanism portion of the copying machine according to the first embodiment as seen from a document table moving direction.

FIG. 4 is a schematic cross-sectional view showing a schematic configuration of a document table moving type copying machine to which the present invention is applied.

FIG. 5 is an external perspective view showing a rack plate in the copying machine according to the second embodiment.

FIG. 6 is an external view showing an example of a conventional document table moving type copying machine.

FIG. 7 is a component diagram of a document table driving mechanism portion of a conventional copying machine.

FIG. 8 is a sectional view of a document table driving mechanism portion of a conventional copying machine.

FIG. 9 is a cross-sectional view of a document table drive mechanism portion of a conventional copying machine as seen from another direction.

[Explanation of symbols]

1 ... Platen 2 ... Crimping plate 3 ... Platen glass 4 ... Rack plate 4a ... 1st butting member 4b ... rack gear 4c ... slit 4p ... pitch line 5 ... Pinion gear 5a ... Second abutting member 5p ... pitch circle 6 ... Rotary support shaft 11 ... Optical system 12 ... Photosensitive drum 13 ... Charging means 14 ... Developing means 15 ... Cleaning means 16 ... Process cartridge 17 ... Feed tray 18 ... Feeding roller 19 ... Conveyor roller 20 ... Transferring means 21 ... Fixing means 22 ... Ejection roller 23 ... Ejection tray

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 63-161440 (JP, A) JP-A 58-154860 (JP, A) JP-A 7-332470 (JP, A) JP-A 7- 114111 (JP, A) JP-A-2-308153 (JP, A) Actual development Sho 63-84134 (JP, U) Actual development Sho 60-107845 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/00-1/00 108 H04N 1/04-1/207 G06T 1/00 G06T 1/60 G03B 27/50 G03G 13/04-13/056 G03G 15/00 107 G03G 15 / 04-15/056 F16H 19/00-37/16 F16H 49/00

Claims (3)

(57) [Claims] 1. An image processing apparatus having a function of reading an image of a document while moving a document table on which a document is set, a holding member for holding the document table, and a holding member parallel to the moving direction of the document table. A rack gear provided in the rack gear, a first abutting member provided in parallel with the rack gear, a pinion gear that meshes with the rack gear to move the document table, and the first pinion gear rotates integrally with the pinion gear. A second abutting member that abuts against the abutting member of 1 to hold the rack gear in a predetermined position with respect to the pinion gear, the holding member, the rack gear, and the first abutting member. And the rack gear and the first butting member are elastically supported with respect to the holding member. 2. The image processing apparatus according to claim 1, wherein a slit is provided in the vicinity of the rack gear integrally formed with the holding member and the first butting member in parallel with the moving direction of the document table. . 3. The amount of change in the height direction of the holding member caused by the inclination of the holding member due to the movement of the platen is δ, and the force required to bend the rack gear by the change amount δ is P. When the second moment of area of the rack gear calculated from the cross-sectional shape of the rack gear is I and the Young's modulus of the material of the holding member is E, the length L of the slit is L.
Is at least L = (192EIδ / P) ^1/3 or more. 3. The image processing apparatus according to claim 2, wherein