JPH09191373A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image reader in which a position of a screen is properly arranged to offer ease of observation, the configuration is simply to offer a low cost, the processing speed is high to hardly receive effect of an external light with immunity against a harmful electromagnetic wave. SOLUTION: A micro film scanner 50 has a screen projection optical path consisting of a ceiling mirror 9 and a mirror 10 and an image read section projection optical path consisting of the ceiling mirror 9 and a mirror 63. A rock enable ceiling mirror base 51 is interlocking with a scanning lever 54 via an arm section 51a at the depth and the ceiling mirror base 51 is rocked in interlocking with the rocking of the scanning lever 54. As the scanning lever 54 is turned clockwise, the ceiling mirror base 51 and the ceiling mirror 9 are turned counter clockwise to select the projection optical path and to scan the image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device which projects and scans an image on a line light receiving sensor or the like to read the image.

[0002]

2. Description of the Related Art A conventional microfilm scanner 100 as shown in FIG. 2 is an example of this type of apparatus. In the microfilm scanner 100, the image light 101 of the microfilm F is bent by projection mirrors 102 and 103 and enlarged and projected on a screen 104. The image light 101 is reflected by the mirror 105 on the back side of the screen 104.
An image is scanned and read or retracted by being guided to the line sensor 106 via the and moving them up and down.

However, in the microfilm scanner having this structure, there is a problem that external light passes through the screen and easily enters the line sensor 106 as indicated by arrow A, and remains as noise on the read image.

Further, since the line sensor 106 is located just behind the screen, it is easily affected by an external electromagnetic wave, and conversely, it also emits a harmful electromagnetic wave.

FIG. 3 is a schematic view of a microfilm scanner 200 which solves the above problems. The micro film scanner 200 rotates a rotating mirror 201 and swings the image light 202 to switch the optical path to the screen 203 and the line sensor 204 and perform image scanning to the line sensor 204.

However, in the case of this optical arrangement, since the rotating mirror 201 is arranged immediately above the projection lens 205, the position of the screen 203 is raised and it becomes difficult to view the projected image.

Therefore, a structure in which the mirror 201 can be moved back and forth has been considered, but the mechanism for moving back and forth becomes complicated and expensive,
In addition, since it takes time to advance and retreat, the reading processing speed of the device is also reduced.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The purpose of the present invention is that the position of the screen is proper and easy to browse, the structure is simple and inexpensive, the processing speed is fast, and An object of the present invention is to provide an image reading apparatus that is resistant to the influence of light and is strong against harmful electromagnetic waves and has a high processing speed.

[0009]

The present invention has been made to achieve the above object, and the first invention is to project an image on a recording medium onto a screen provided on the front surface of the apparatus. In an image reading apparatus that switches between an observation state of observing with an image reading apparatus and a reading state of projecting and reading the image on a reading unit, a projection lens provided below the apparatus for projecting an image,
A swingable first reflecting member which is provided above the screen and reflects projection light from the projection lens;
A second reflecting member for guiding the projection light reflected by the reflecting member to the screen, and a second reflecting member provided below the second reflecting member for guiding the projection light reflected by the first reflecting member to the image reading unit. It is characterized in that it has three reflecting members, and the first reflecting member swings to switch between an observing state and a reading state.

In a second aspect based on the first aspect, the first reflecting member rotates to guide the projection light to the image reading section, and the image reading section is moved in conjunction with the rotation of the first reflecting member. It is characterized in that the image is read by moving it back and forth in the optical axis direction.

A third invention is characterized in that, in the first invention, the image reading section is provided on the back side of the second reflecting member.

A fourth invention is characterized in that, in the third invention, a reflecting surface of the first reflecting member faces downward, and a reflecting surface of the third reflecting member faces a rear side of the apparatus.

[0013]

1 is a schematic view of a microfilm scanner 50 which is an image reading apparatus adopting the present invention.

Microfilm scanner 5 according to the invention
0 is a screen projection optical path formed by the first reflecting member ceiling mirror 9 and the second reflecting member mirror 10 shown in FIG. 1, and the ceiling mirror 9 and the third reflecting member mirror 63 shown in FIG. And an image reading unit projection optical path formed by.

Reference numeral 11 is a machine casing, and 2 is a light source. The illumination light emitted from the light source 2 is condensed by the spherical reflected light 3 and the field lens 4 and reflected by the mirror 7 to illuminate the microfilm F sandwiched between the glass plate pair (not shown). The light transmitted through the microfilm F is projected by the projection lens 5 onto the screen 6 or the line sensor 60 serving as an image reading unit. The line sensor 60 is provided behind the reflection mirror 10, and as shown in FIG. 4, a light receiving element group 107 arranged in a line with the substrate 106 and a silicon resin for protecting the light receiving element group 107 from oxidation and external force. Clearing unit 108
It is composed of

The ceiling mirror 9, which is the first reflecting member, is fixedly mounted on the ceiling mirror stand 51 with its reflecting surface facing downward, and the ceiling mirror stand 51 intersects the reflecting surface of the ceiling mirror 9 with the projection optical axis. It is provided so as to be swingable around the line 52. The ceiling mirror base 51 has an arm portion 51a on the inner side thereof, and a groove 51b is carved at the tip thereof. The groove 51b has a "dogleg" shape in which a portion extending radially with respect to the swing center 52 and a portion inclined are continuously connected.

A scanning lever 54 is swingably provided on a rotary shaft 53 provided at the rear of the device 50. A protruding engaging shaft 54a is provided at the tip of the scanning lever 54,
The groove 51b of the ceiling mirror base 51 is engaged. Due to this engagement, the ceiling mirror base 51 also swings in conjunction with the swing of the scanning lever 54. A cam 55 is also rotatably provided on the rotating shaft 53. The cam 55 is an optical path length correction cam 55.
It has two cam surfaces, that is, a and an attitude regulating cam 55b.

On the other hand, below the rotary shaft 53, there is a slide base 5.
6 is attached to the slide shaft 57 so as to be reciprocally movable. A sensor holder 59 is swingably held on the slide table 56. The line sensor 6 is mounted on the sensor holder 59.
0 and the slit 61 are fixed. The center of swing of the sensor holder 59 coincides with the light receiving line of the line sensor 60. The slide base 56 has an arm portion 56a having a roller 58 at its tip, and the sensor holding base 59 has an arm portion 59a.
Are provided, and are brought into contact with the optical path length correction cam 55a and the attitude regulating cam 55b, respectively, by the urging force of the tension spring 62. That is, the position and orientation of the line sensor 60 are determined by the rotation angle of the cam 55.

Below the reflection mirror 10, as shown in FIG. 7, the reflection surface of the reflection mirror 6 is directed toward the rear side of the apparatus in order to guide the projection light from the ceiling mirror 9 to the line sensor 60.
3 is fixed.

FIG. 5 is a diagram showing a drive transmission portion for the scanning lever 54 and the cam 55. The output of the forward / reverse scan motor 64 is reduced by the gear 65 and transmitted to the cam 55.
It is further decelerated by the gear 66 and transmitted to the scanning lever 54. Further, the scanning lever 54 can be controlled in an arbitrary posture by a detection unit (not shown).

In the microfilm scanner 50 having the above-described structure, the scanning lever 54 is normally stopped at the position shown in FIG. 1, and the image path of the microfilm F is projected on the screen 6, which is a so-called observing optical path. Is forming. The optical path is folded so as to intersect with the ceiling mirror 9 and the reflection mirror 10, and is guided to the screen 6.

When an image reading switch (not shown) is pressed, the scanning motor 64 rotates to rotate the scanning lever 54 counterclockwise. Along with this, the ceiling mirror base 51 and the ceiling mirror 9 rotate clockwise to swing the image light. As shown in FIG. 6, when the light at the end of the image enters the line sensor 60 via the reflection mirror 63, the image reading is started.
Further, after the image center reading shown in FIG. 7 is reached and the image end shown in FIG. 8 is reached, the scanning motor 64 starts reverse rotation,
It returns to the observation state of FIG.

Further, with the rotation operation of the scanning lever 54, the positions and postures of the line sensor 60 and the slit 61 change as follows. At the start of image reading (Fig. 6),
At the end, the posture is the highest. Then, when the image center is read (FIG. 7), the posture changes to the frontmost intermediate posture. Further, when the image reading is completed (FIG. 8), the posture returns to the rearmost position and changes to the most downward posture. That is, the optical path length is always corrected so that the image forming position of the projected image and the light receiving line position of the line sensor 60 coincide with each other, and the inclination is corrected so that the image light enters the line sensor 60 at a constant angle. ing. The purpose is to avoid image distortion due to a change in optical path length, and to avoid the influence of dust adhering to the line sensor 60 as much as possible. FIG. 12 shows the distortion of the read image that occurs when the optical path length correction is not performed.

The sensor holder 59 has a double structure as shown in FIG. 9, and the line sensor 60 can be rotated around the light receiving line together with the adjusting table 68 by loosening the adjusting screw 67 as a locking means. It is possible. That is, the incident angle of the projection light with respect to the line sensor 60 can be arbitrarily selected. For example, even if dust adheres within the light receiving angle of the line sensor 60 in FIG. 9 and streaks occur in the image, this can be avoided by changing the angle of the line sensor 60 as shown in FIG.

FIG. 11 is a diagram showing the relationship between the rotating operation of the scanning lever 54 and the moving (scanning) operation of the image projected on the line sensor 60. The scanning lever 54 has a constant angular velocity d.
When rotated at β, the angular velocity of the ceiling mirror 9 rotating via the arm portion 51a is dγ1 <dγ2 <dγ3, (dγ
n = dγn ′), and the image becomes slower toward the end. However, if the ceiling mirror 9 rotates at a constant speed, the moving (scanning) speed of the image forming plane 69 becomes faster on the contrary to the image end portion. Therefore, the moving (scanning) speeds of the image forming plane 69 are approximately maintained at a constant speed dx after being offset and corrected. The groove 51b has a "doglegged" shape in order to shorten the time required for transition between the reading state and the observing state.

[0026]

As described above, the following effects can be obtained by the present invention.

According to the first aspect of the invention, since the projection optical path is efficiently folded, the screen can be arranged at an appropriate position and it is easy to view. Further, since switching between the observation optical path and the reading optical path is performed only by rotating the first reflecting member, the configuration is simple and the cost is low.

According to the second aspect of the invention, since the scanning and scanning of the image and the switching of the optical path are performed by a series of rotational movements of the first reflecting member, the processing speed of the scanning of the image is fast.

According to the third aspect of the invention, since the image reading section is provided on the back side of the second reflecting member, it is unlikely to be affected by external light passing through the screen. Further, since the image reading unit can be arranged on the back side of the apparatus, a structure strong against harmful electromagnetic waves can be realized.

According to the fourth aspect of the invention, since the reflecting surface of the first reflecting member relating to image reading faces downward and the reflecting surface of the third reflecting member faces the inner side of the apparatus, the external light transmitted through the screen. Does not irradiate the reflecting surface of the reflecting member, so it is unlikely to be affected by outside light.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of an image reading apparatus according to the present invention.

FIG. 2 is a vertical sectional view showing a first conventional example of an image reading apparatus.

FIG. 3 is a vertical cross-sectional view showing a second conventional example of the image reading apparatus.

FIG. 4 is an enlarged view of a line sensor unit of the image reading apparatus.

FIG. 5 is a sectional view of a driving unit of the image reading apparatus according to the present invention.

FIG. 6 is a vertical cross-sectional view of the image reading apparatus according to the present invention at the start of reading.

FIG. 7 is a vertical cross-sectional view of the image reading apparatus according to the present invention during image center reading.

FIG. 8 is a vertical cross-sectional view of the image reading apparatus according to the present invention at the end of reading.

FIG. 9 is an enlarged view of an image reading unit of the image reading apparatus according to the present invention.

FIG. 10 is an enlarged view of an image reading unit of the image reading apparatus according to the present invention.

FIG. 11 is a diagram showing a scanning lever and an image scanning speed of the image reading apparatus according to the present invention.

FIG. 12 is a diagram showing image distortion due to a change in optical path length of the image reading apparatus.

[Explanation of symbols]

 F film 6 screen 9 reflection mirror (first reflection member) 10 reflection mirror (second reflection member) 51a arm 54 scanning lever 55a optical path length correction cam 55b attitude control cam 60 line sensor (image reading unit) 63 reflection mirror (third) (Reflecting member)

Claims (4)

[Claims] 1. An image reading apparatus which switches between an observation state in which an image on a recording medium is projected on a screen provided on the front surface of the apparatus for observation and a reading state in which an image is read by being projected on an image reading unit. A projection lens for projecting an image, a swingable first reflecting member provided above the screen for reflecting projection light from the projection lens, and reflected by the first reflecting member. A second reflecting member that guides the projected light to the screen, and a third reflecting member that is provided below the second reflecting member and that guides the projected light reflected by the first reflecting member to the image reading unit. The image reading apparatus is characterized in that the first reflecting member swings to switch between an observation state and a reading state. 2. The first reflecting member rotates to guide projection light to the image reading unit, and the image reading unit is moved back and forth in the optical axis direction in association with the rotation of the first reflecting member to display an image. The image reading apparatus according to claim 1, wherein the image reading apparatus reads. 3. The image reading apparatus according to claim 1, wherein the image reading unit is provided on the back side of the second reflecting member. 4. The image reading apparatus according to claim 3, wherein a reflecting surface of the first reflecting member faces downward, and a reflecting surface of the third reflecting member faces a rear side of the apparatus.