JP3363582B2 - Document reading device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading device. More specifically, the present invention relates to a static document reading apparatus that scans a document placed on a document table by a reciprocating scanning unit.

[0002]

2. Description of the Related Art Conventionally, as a document reading device in a copying machine, a facsimile, a scanner or the like, a document reading device for exposing and reading a document by reciprocating a document table on which a document is placed, and reciprocating an optical part. As a result, a method of exposing and reading an original (a static original reading apparatus) and the like have been developed.

Of these, the static original reading apparatus is provided with a first scanning section which is provided with an illuminating member and a first mirror and moves at a scanning speed, a second mirror and a third mirror, and is 1 / th of the scanning speed.
It consists of an optical part having a second scanning part that moves by 2, and can use simple parts such as pulleys and wire ropes.
It is generally adopted because of its relatively simple mechanism and structure (Japanese Patent Publication No. 4-51014, Japanese Patent Publication No. 4-41014).
51015).

FIG. 2 is a schematic view showing the internal structure of the entire conventional copying machine described in the above publication, FIG. 3 is a perspective view of an optical section, FIG. 4 is an exploded perspective view of a second scanning section, and FIG. It is a top view of the 2nd scanning part. As shown in FIG. 2, the inside of the copying machine main body (1) is divided by the partition plate (11) into the upper chamber (1
2) and a lower chamber (13), and an optical system (2) for scanning exposure of a document (D) is provided in the upper chamber (12).
A copy processing unit (4) for forming a copy image on the copy paper (P) and a copy paper transporting unit (8) are provided in 3).

Here, the optical system (2) is composed of a luminous body (3
1), a light source (21) including a main reflection plate (32) and a sub reflection plate (33), a first mirror (22), a second mirror (23), a third mirror (24), a lens (25). , And a plane reflecting mirror (26), and contacts by moving the light source (21) and the first, second and third mirrors (22), (23) and (24) in the direction shown by the arrow (A). The document (D) on the glass (14) can be scanned and exposed. Then, the light source (21) and the first mirror (2
2) moves integrally, the second mirror (23) and the third mirror (24) also move integrally, and the former moving speed is set to be twice the latter moving speed. The light source (21), the first mirror (22) and the second mirror (2
3) and the third mirror (24) form a scanning optical unit (2 ').

Further, as the copy paper carrying section (8), a paper feeding roller (81), a paper feeding path (83) and a carrying roller (8)
5), registration roller (86), heat fixing roller (8
8) and a discharge roller (89), and by driving the paper feed roller (81), the paper feed cassette (16)
Take out the copy paper (P) for one sheet from the copy processing unit (4)
To transfer the toner image to the heat fixing roller (88)
After the toner image is heated and fixed by the
8) It is designed to discharge upward.

As the copy processing section (4), the photosensitive drum (41) which rotates in the direction shown by the arrow (C) in FIG.
Around the periphery of the charging charge (42), blank lamp (B), developing device (43), transfer charger (44),
The separation member (45) and the cleaner (46) are arranged in this order, and a document image is formed on the outer surface of the photosensitive drum (41) uniformly charged by the charging charger (42) to form an electrostatic latent image. An image is formed, and the electrostatic charge on the peripheral portion where the electrostatic latent image is not formed is removed by the blank lamp (B), and then visualized as a toner image by the developing device (43).
The transfer charger (44) transfers the toner image onto the copy paper (P), and the cleaner (46) collects the residual toner.

Then, as shown in FIGS.
The scanning unit (5) has the following configuration. That is, the second mirror (23) and the third mirror (24) are attached to predetermined positions of the support frame body (51), and a pair of slide members (52) and 1 are provided at one end predetermined positions.
Install one pulley (53) and put it in place at the other end.
A number of pulleys (54) are attached. Then, the end member (5) rotatably connected to the support frame main body (51).
A pair of slide members (56) are attached at predetermined positions in 5). The pulleys (53) and (54) are mounted at the same height position and in a relative relationship perpendicular to the scanning direction. In addition, the slide member (5
2) and (56) are also mounted at the same height position in the normal state, and each pair of slide members (5
2) and (56) are attached in a relative relationship perpendicular to the scanning direction. Further, the support frame main body portion (51) is provided with a mirror mounting portion (57), and the mirror mounting portion (57).
And the slide supports (58) and (59) are fixedly connected by shafts (60) and (61). Further, the end member (55) has the slide support portion (5).
The hole (6) for loosely inserting the shaft (62) attached at the predetermined position of (9)
3), and a bolt (65) for preventing the bearing (64) from falling off is attached to the shaft (62). The slide members (52) and (56) are respectively sliders (66) attached to the copying machine body (1).
(See FIG. 3), contact the upper surface of the pulley (53), (5
The drive wires (69) and (70) wound around 4) scan the second scanning section (5) at a predetermined moving speed.

The conventional second scanning unit (5) sets the second mirror (23) and the third mirror (24) at a right angle, and at the same time, sets the second mirror (23) and the third mirror (24) together. Must be accurately attached to the support frame body (51) so that the angle is 45 ° with respect to the optical axis. For that purpose, for example, an optical adjustment mechanism of a document reading device (Japanese Patent Application No.
No. 300618), the adjustment of the mirror perpendicularity (see FIG. 6) and the mirror holding angle (see FIG. 7) using an optical adjustment jig with laser light.
Then, the second mirror (23) and the third mirror (24) are assembled to the support frame main body (51) with high accuracy and adjusted.

Therefore, the adjustment of the perpendicularity of the mirror and the adjustment of the mirror holding angle using the optical adjustment jig by the laser light shown in FIGS. 6 and 7 will be described. 6 and 7, the document reading apparatus includes a light source (71) and a first mirror (7).
2), a second mirror (73), a third mirror (74), a mirror holder (75), a condenser lens (76), and a solid-state image sensor (77). It differs from the document reading apparatus described in that it mainly includes a solid-state imaging device (77). Then, the optical adjusting jig (90) with the laser light is provided with a reference surface (91) for adjusting the mirror perpendicularity and a reference surface (9) for adjusting the mirror holding angle.
2) It has a positioning pin (93), and is provided with a laser emitting part, a polarization beam splitter, a 1/4 wavelength plate, a slit, and a laser receiving element inside. To adjust the perpendicularity of the mirror, as shown in FIG. 6, the reference surface (91) of the optical adjustment jig (90) is brought into contact with the second mirror (73), and the laser light from the laser emission portion is polarized into a polarized beam. Pass the splitter and the quarter-wave plate, and the third mirror (7
The light reflected in 4) is again passed through the quarter wavelength plate, reflected by the polarization beam splitter, and the amount of light received is measured by the light receiving element through the slit. If the predetermined amount of light is not received, a mirror perpendicularity adjustment mechanism (not shown) is used until the second mirror (73) and the third mirror (74) are at a right angle so that the predetermined amount of light is received. Adjust while measuring the amount of received light. Adjustment of the mirror holding angle is performed as shown in FIG.
The alignment pin (93) of the optical adjusting jig (90) is inserted into the insertion hole of the document reading device, and the reference surface (9
2) is brought into contact with a predetermined position of the document reading device, and laser light is emitted from the optical adjustment jig (90) to the third mirror (74) whose perpendicularity is adjusted to adjust the mirror holding angle. This is done (details omitted).

Then, in the second scanning unit (5) shown in FIGS. 2 to 5, the slide supporting units (58) and (59) are provided.
Between the mirror mounting portion (57) and the shafts (60), (6
1) is fixedly connected, while the end member (55) is rotated with respect to the shaft (62), and the shaft (6)
0) and (61) are the second mirror (23) and the third mirror (2).
It is set at a position apart from the extension line of the intersection axis of the reflecting surface of 4). Therefore, as shown in FIG. 8, the second mirror (23) is affected by the processing accuracy of the slide support parts (58), (59), the end member (55), the dimensional error based on the assembly accuracy, the assembly error, and the like. , If the third mirror (24) is fixed with an error (θ) tilt from 45 degrees with respect to the reading optical axis,
Even if the mirror (23) and the third mirror (24) are adjusted at a right angle, the height position of the optical axis and the optical path length change, which makes it impossible to accurately scan and read the image. I will end up. Therefore, the mirror mounting portions (57) of the second mirror (23) and the third mirror (24) are formed by using the optical adjustment jig with laser light as shown in FIG.
It is necessary to adjust the fixed state between the slide support parts (58) and (59). However, the adjustment is delicate and complicated, and requires highly skilled work. Further, in order to reduce the machining accuracy of the parts, the dimensional error based on the assembly accuracy, and the assembly error, it is necessary to use the parts with high processing accuracy, but it is impossible to completely eliminate the mechanical error and the assembly error. There is a drawback that the processing cost becomes high in order to improve the processing accuracy of the parts.

[0012]

SUMMARY OF THE INVENTION The present invention was devised to solve the above-mentioned drawbacks of the prior art, and includes a holding member for the second mirror and the third mirror in the second scanning section, It can be mounted easily with a moving member, and even if the mounting angle varies with the design angle, no special angle adjustment is required, and the manufacturing cost is low. An object of the present invention is to provide a type original reading device.

[0013]

In order to solve the above-mentioned problems, the present invention comprises a first scanning section which comprises an illuminating member and a first mirror and which moves at a scanning speed, a second mirror and a third mirror. In a static document reading apparatus having a second scanning unit that moves at half the scanning speed, the second scanning unit includes a mirror holding member that holds the second mirror and the third mirror at a right angle, It is characterized by comprising a moving member provided at an end of the mirror holding member, and a positioning reference portion of the mirror holding member and the moving member is arranged on an extension line of an intersection axis of the reflecting surfaces of the second mirror and the third mirror. And

The moving members may be provided at both side ends of the mirror holding member. Further, moving members may be provided at both ends of the mirror holding member, one moving member may be fixed to the mirror holding member, and the other moving member may be rotatable around the positioning reference portion. . Further, the moving member is composed of a first moving member provided at one end of the mirror holding member and a second moving member and a third moving member provided at the other end of the mirror holding member, and the positioning reference portion is positioned. A reference member, and the positioning reference members are respectively provided on extension lines of an axis of intersection of the reflecting surfaces of the second mirror and the third mirror at both end portions of the mirror holding member, and one end portion of the mirror holding member. The first moving member is fixed on the basis of the positioning reference member, the second moving member is fixed on the other end of the mirror holding member on the basis of the positioning reference member, and the third moving member is centered on the positioning reference member. It may be rotatably disposed.

[0015]

According to the above construction, since the positioning reference portion of the mirror holding member and the moving member is arranged on the extension line of the axis of intersection of the second mirror and the third mirror, the mirror holding member of the second scanning portion. When mounting the and moving member, the mounting angle based on the processing accuracy and assembly accuracy of the parts is not affected by the error,
The height position of the optical axis and the optical path length are always constant.

Further, if the moving member is provided at both end portions of the mirror holding member, the second scanning portion can travel stably. Also, if the other moving member is rotatable,
Even if the traveling guide is distorted, the effect of the distortion of the traveling guide is absorbed by the rotation of the other moving member and an unreasonable force acts on the mirror holding member and one of the moving members. There is no. Further, even if the traveling guide for one moving member is distorted, the distortion does not affect the other moving member.

Further, when the moving member is composed of the first, second and third moving members, of which the third moving member is rotatable, the force from the wire or the like for running the second scanning member. The vehicle travels stably along the traveling guide without being affected by the direction of action.

[0018]

The present invention will be described in more detail with reference to the following examples. Of course, the present invention is not limited to the following examples. FIG. 1 is an exploded perspective view of a second scanning unit in a static document reading device of a copying machine. The other structure is the same as that of the conventional copying machine described above, and therefore the description thereof is omitted.

In FIG. 1, the second scanning unit (S) is
A mirror holding member (103) having a mirror (101) and a third mirror (102), a first moving member (106), a second moving member (112), and a third moving member (11).
7) and. Then, the second mirror (10
1) and the third mirror (102) include a mirror holding member (10).
3) The mirrors are attached and held so that the reflecting surfaces of both mirrors are at right angles.

Here, the second mirror holding member (103)
In order to mount and hold the mirror (101) and the third mirror (102) at a right angle, for example, the second mirror (101) and the third mirror (102) are fixed by an optical adjustment jig as shown in FIG. It can be done by adjusting so that and are at right angles. On both end surfaces of the mirror holding member (103), a positioning reference axis (10) is provided at a position on an extension line of an intersection axis of the reflecting surfaces of the second mirror (101) and the third mirror (102).
4) and (105) are projected outward. A positioning reference hole (107) is formed in the first moving member (106), and a pair of slide parts (109) and a pulley (110) are provided. Then, the positioning reference shaft (104) protruding from the one end surface of the mirror holding member (103) is inserted into the positioning reference hole (107) of the first moving member (106), and the mirror holding member (103). After the positioning of the first moving member (106) and the first moving member (106) is performed, both of them are fixedly fixed in place by screws (108).

The second moving member (112) is provided with a positioning reference hole (113) and a pulley (11).
6) is provided. Also, the third moving member (117)
A pair of slide parts (119) are provided on the base plate, and a positioning reference hole (120) is formed in the upright portion so as to face each other. Then, the mirror holding member (10
3) Positioning reference shaft (10
5) is the positioning reference hole (1) of the second moving member (112).
After being inserted into 13) and the mirror holding member (103) and the second moving member (112) have been positioned, they are fixedly fixed in place by screws (114). Further, the positioning reference shaft (105) is loosely inserted into the positioning reference hole (120) of the third moving member, and the third moving member (117) is rotatable about the positioning reference shaft (105). . The positioning reference hole (120)
A bearing (not shown) for facilitating the rotation of the positioning reference shaft (105) may be provided in the shaft, and a shaft stopper member (121) is attached to the tip of the positioning reference shaft (105). The third moving member (117) and the positioning reference shaft (105) are not separated.

Then, the pulleys (110), (1) provided on the first moving member (106) and the second moving member (112).
16) drive wires (111) and (11), respectively.
5) is wound and stretched. In addition, the first moving member (1
06), the slide parts (109), (119) provided on the third moving member (117) come into contact with a guide (not shown) and slide on the guide. Needless to say, the reciprocating movement of the moving member is not limited to the one having the above-mentioned configuration, and an appropriate one such as one having a configuration of sliding across the slide shaft can be adopted.

Therefore, when the second scanning unit (S) is assembled, the mounting angles of the mirror holding member (103) and the first moving member (106) are increased due to the processing accuracy of the parts, the dimensional error based on the assembly accuracy, and the assembly error. Angle error (θ) with respect to the design angle
Even if the third moving member (11
Since 7) is rotatable with respect to the positioning reference shaft (105), the slide members (109), (11
9) can slide on the guide without floating, and as shown in FIG. 9, the height position of the optical axis and the optical path length do not change, and the mirror holding as shown in FIG. There is no need to adjust the angle. Therefore, the second scanning unit (S) is moved at a scanning speed ½ that of the first scanning unit, and the original can be read accurately.

Next, the relationship between the height position of the optical axis and the optical path length of the present invention shown in FIG. 9 will be described in detail with reference to FIG. Figure 1
At 0, the reflecting surface of the second mirror and the reflecting surface of the third mirror intersect at a right angle, and the intersection axis point is T. Then, the designed reflecting surface of the second mirror is HT, and the reflecting surface of the third mirror is GT, and an error θ occurs in the mounting angle.
It is assumed that the three mirrors rotate about the intersection point T, and the actual reflecting surface of the second mirror becomes DT and the actual reflecting surface of the third mirror becomes CT. Here, the light incident from A is reflected at points P and Q,
It is assumed that the light is emitted to B. Mirror CT and DT are orthogonal (∠CT
D = 90 °), and let R be the intersection of the extension line of AP and the extension line of DT: ∠APC = ∠RPT = ∠TPQ ∴ △ PTR ΔPTQ ∴∠PRT = ∠PQT = ∠BQD, RT = QT Therefore, AP and BQ are parallel.

On the other hand, assuming that the light is incident from A and reflected at the point E of the mirror GT in the designed arrangement of the mirrors, the light is incident at an angle of incidence of 4 at the point E of the mirror GT.
The light enters at 5 °, is reflected at 45 °, is incident on the point F of the mirror HT at an incident angle of 45 °, and is reflected at 45 °. If the intersection of the extension line of AE and the extension line of HT is S, ∠AEG = ∠SET = ∠TEF = 45 ° ∴ △ ETS △ ETF ∴∠EST = ∠EFT = ∠BFH = 45 °, ST = T
F and the point F is on BQ.

Therefore, even if the second mirror (101) and the third mirror (102) are attached to the mirror holding member (103) with an error of the angle θ from the design angle, the light is emitted. The direction is always B, and the height position of the optical axis is always constant. The change in the optical path length in this case is (PQ + QF)-(PE + EF) = (PR + RS)-
(PE + ES) = PS−PS = 0, and the optical path length also becomes constant.

In the above embodiments, the first moving member is provided at one end of the mirror holding member and the second moving member is provided at the other end thereof.
A third moving member is provided, the first moving member is fixed at one end of the mirror holding member with reference to the positioning reference axis, and the second moving member is fixed at the other end of the mirror holding member using the positioning reference axis. The second scanning unit, which is fixed to the reference and in which the third moving member is rotatably arranged around the positioning reference shaft, has been described. However, the second scanning unit is not limited to such a structure, and the point is that the second scanning unit is provided at the mirror holding member that holds the second mirror and the third mirror at a right angle and at the end of the mirror holding member. It is sufficient if the positioning member is composed of a moving member, and the positioning reference portions of the mirror holding member and the moving member are arranged on an extension line of the intersecting axis of the reflecting surfaces of the second mirror and the third mirror.
It does not require a few moving members, and the moving member may not be rotatable but may be fixed. Further, the positioning reference portion is not limited to the one using the positioning reference shaft, and for example, one including a hole provided at the positioning reference position and a protrusion fitted to this,
Or, a hole provided at each of the positioning reference positions,
It goes without saying that appropriate means such as a pin or screw attached to this can be adopted.

Although the embodiment of the present invention has been described as a static type original reading device in a copying machine, the static type original reading device of the present invention is not limited to that for a copying machine, and may be a facsimile, a scanner or the like. It is obvious that the present invention can also be applied to the static type document reading apparatus in.

[0029]

Since the present invention is configured as described in detail above, it has the following effects. When mounting the mirror holding member and the moving member of the second scanning unit, even if an error occurs in the mounting angle based on the processing accuracy and the assembly accuracy of the component with respect to the designed mounting angle, the positioning reference unit causes the second mirror and the second mirror to move. Since it is provided on the extension of the axis intersecting with the three mirrors, the height position of the optical axis and the optical path length are always constant, and are not affected by the mounting angle error. Therefore, it is not necessary to increase the component accuracy and the assembly accuracy, and even if the component accuracy and the assembly accuracy are lower than before, the height position of the optical axis,
The optical path length can be made constant, and the original can be read satisfactorily and accurately. Furthermore, it is possible to provide a static document reading apparatus with low manufacturing cost.

Further, since it is not necessary to adjust the angle in assembling the mirror holding member and the moving member, no skill is required and the assembling time can be shortened. Further, since maintenance during use is unnecessary, maintenance and management becomes easy. Further, if the moving member is provided at both end portions of the mirror holding member, the second scanning unit can be stably moved.

When the other moving member is rotatable, even if the traveling guide is distorted, the effect of the distortion of the traveling guide is absorbed by the rotation of the other traveling member, and the mirror is absorbed. No excessive force acts on the holding member and the one moving member. Further, even if the traveling guide for one moving member is distorted, the distortion does not affect the other moving member.

Further, when the moving member is composed of first, second and third moving members, and of which the third moving member is rotatable, a wire for moving the second scanning member is used. It is possible to travel stably on the travel guide without being affected by the direction in which the force acts.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a second scanning unit according to the present invention.

FIG. 2 is a schematic diagram showing an internal configuration of a conventional copying machine.

FIG. 3 is a perspective view of the optical unit shown in FIG.

FIG. 4 is an exploded perspective view of a second scanning unit of FIG.

5 is a plan view of a second scanning unit of FIG.

FIG. 6 is a schematic view of the squareness adjustment of the second mirror and the third mirror of the second scanning unit by an optical adjustment jig using a laser.

FIG. 7 is a schematic view of the attachment angle adjustment of the second mirror and the third mirror of the second scanning unit to the mirror holding member by the optical adjustment jig.

FIG. 8 is a schematic diagram showing a height position of an optical axis and an optical path length due to an error in mounting angle of a second mirror and a third mirror to a mirror holding member in a conventional second scanning unit.

FIG. 9 is a schematic view showing a height position of an optical axis and an optical path length due to an attachment angle error of a second mirror and a third mirror to a mirror holding member in a second scanning unit of the present invention.

10 is a diagram showing the relationship between the height position of the optical axis and the optical path length in FIG.

[Explanation of symbols]

S second scanning unit 101 Second mirror 102 Third mirror 103 Mirror holding member 104, 105 Positioning reference axis 106 first moving member 112 Second moving member 117 Third moving member 107, 113, 120 Positioning reference holes 109 and 119 slide parts

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-63-313959 (JP, A) JP-A-61-203440 (JP, A) JP-A-7-226828 (JP, A) JP-A-6- 22097 (JP, A) Actual development Sho 61-165516 (JP, U) Japanese Patent Publication 4-51014 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/04-1 / 207 G03G 13/04-13/056 G03G 15/00 107 G03G 15/04-15/056

Claims (4)

(57) [Claims] 1. A first scanning unit that includes an illuminating member and a first mirror and moves at a scanning speed; a second scanning unit that includes a second mirror and a third mirror and moves at a half of the scanning speed; And a mirror holding member for holding a second mirror and a third mirror at a right angle, and a stationary document reading device for scanning and reading a document placed on a document table. A moving member provided at an end of the member, and a positioning reference portion for the mirror holding member and the moving member is arranged on an extension line of the intersection axis of the reflecting surfaces of the second mirror and the third mirror. Stationary document reader. 2. The stationary document reading apparatus according to claim 1, wherein the moving member is provided at both end portions of the mirror holding member. 3. A moving member is provided at both end portions of the mirror holding member, one moving member is fixed to the mirror holding member, and the other moving member is rotatable about a positioning reference portion. The static document reading device according to claim 2, wherein 4. The positioning member includes a first moving member provided at one end of the mirror holding member and a second moving member and a third moving member provided at the other end of the mirror holding member. And a positioning reference member, the positioning reference member being provided on each of the extension lines of the axes of intersection of the reflecting surfaces of the second mirror and the third mirror at both end portions of the mirror holding member. The first moving member is fixed at the side end portion with the positioning reference member as a reference, the second moving member is fixed at the other end portion of the mirror holding member with the positioning reference member as a reference, and the third moving member is the positioning reference member. A static original reading device, which is arranged so as to be rotatable around the.