JP2885975B2 - Image projection 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 projection apparatus for projecting an image on a screen and observing the image, and in particular, has an image rotation function of obtaining a projection image at an arbitrary angle by using an image rotation optical system. The present invention relates to an image projection device.

[0002]

2. Description of the Related Art Conventionally, as this type of apparatus, there is a microfilm reader and a microfilm reader printer. A microfilm reader is a device that enlarges and projects an image of a microfilm on a screen and observes it. A microfilm reader printer is a device that can further copy and print a projected image on paper as necessary. In an image shot on a microfilm, each frame is not always oriented in the same direction. This is due to human or mechanical mistakes during photographing and uneven orientation of characters and designs. For this reason, it is necessary to provide an image rotating means in the microfilm reader printer so that an upright image can be obtained when an image on the microfilm is projected and copied. As one means,
There is known a method in which a prism is rotatably arranged around an optical axis in a print optical path to rotate an image. As a prism for image rotation, a trapezoidal prism is mainly used. This prism has the optical property of rotating an image at an angle twice the rotation angle by rotation about an axis parallel to the total reflection surface. That is, according to the optical properties of the trapezoidal prism, it is possible to rotate an image by 90 ° by rotating the trapezoidal prism by 45 °.

[0003]

However, when a trapezoidal prism is provided, the following problems occur. Normally, in the case of a microfilm reader and a reader printer, the microfilm may be in the form of fish, jacket, roll, etc.
It has microfilm transport means called a carrier. By using this, the operator can move each frame of the microfilm and project a desired microfilm image while visually recognizing the image on the screen. However, when the trapezoidal prism is used, the moving direction of the carrier, that is, the moving direction of the microfilm and the moving direction of the projected image on the screen are relatively shifted depending on the direction of the prism. As a result, the operator was confused, and it took time to obtain a desired projection image.

The above points will be described with reference to FIGS. 10 to 12 which show the relationship between the direction of the trapezoidal prism and the direction of the film image. In these figures, the projected image on the screen 8 is shown in the direction of arrow A or B. In order to move the microfilm F, it is necessary to move the microfilm F in the A 'or B' direction, respectively. That is, as shown in each figure, the direction in which the image is to be moved on the screen 8 and the microfilm F
The direction in which is to be moved depends on the direction of the prism 5. Therefore, even when the operator starts operating the microfilm reader to observe the image of the microfilm and tries to obtain a desired microfilm image, the direction in which the film should be moved is not known, and confusion is often caused. Also, in the case of FIG. 11, in order to move the image on the screen 8 up and down (left and right),
Film F must be moved left and right (front and back),
Physiological pain was given to the operator.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems of the related art, and has as its object to provide an image projection apparatus that always keeps a constant relationship between a moving direction of a film and a moving direction of a screen projection image when power is turned on.

[0006]

In order to achieve the above object, the present invention relates to an image projection apparatus for projecting an image on a screen and observing the image, wherein an image rotation prism is provided in a projection optical path, and a projection optical axis is provided. An image rotation optical system rotatably mounted around the device, and driving means for rotating the image rotation optical system. When the power of the apparatus main body is turned on, the image rotation optical system is referenced by the driving means. After being rotated to the stop direction, it is stopped. Further, when the power is turned on, a switching unit and a selection unit that can select whether or not to rotate the image rotation prism to the reference stop direction by the driving unit may be provided. Further, it is preferable that the reference stop direction of the image rotating prism is a direction in which the moving direction of the screen projection image with respect to the moving direction of the image coincides with the left, right, up and down (front and back). Further, the reference stop direction of the image rotation prism may be switched to an arbitrary direction.

[0007]

In the image projection apparatus having the above structure, when the operator turns on the power of the apparatus main body, the driving means stops the rotation of the prism of the image rotation optical system in a fixed direction as a reference, thereby providing a desired film. Image retrieval becomes easy. In addition, when the moving direction of the screen projection image, which corresponds to the moving direction of the image, is made to coincide with the moving direction of the screen, the operator is most easily handled. Further, by providing the prism reset selection switch, it is possible to cope with a case where temporary work is interrupted.
Further, the reference stop direction of the prism can be arbitrarily switched, so that the operator can freely set the reference stop direction.

[0008]

1 to 5 show a first embodiment of the present invention.
It will be described based on. 1 and 2 are schematic configuration diagrams of a microfilm reader printer as an image projection device, showing a reader state and a printing state, respectively. In the figure, F is a microfilm, 11 is a lighting lamp,
12 is a spherical mirror. The illumination light from the illumination lamp 11 illuminates the microfilm F via the mirror 13 and the condenser lens 14. Reference numeral 15 denotes a projection lens, 31 denotes a prism holder as an image rotation optical system described later, 16 and 17 denote reader mirrors that form a reader optical path, and the mirror 17 is provided rotatably about a shaft 18. . 19 is a screen. Reference numerals 21 and 22 denote print mirrors that form a printer optical path, and are disposed so as to face the scan case 23 at right angles to each other. The scan case 23 is moved by a driving unit (not shown) in a direction perpendicular to the reader optical path to expose and scan an image. Reference numeral 24 denotes a photosensitive drum, around which a well-known image forming means such as a charger, a developing unit, and a transfer unit (not shown) are arranged, and copying is performed on a copy sheet P by electrophotography.
Reference numeral 25 denotes a paper cassette, and reference numeral 26 denotes a discharge tray. Also,
Reference numeral 27 denotes a light receiving sensor provided on the lower surface of the scan case 23 for receiving image projection light and detecting the image density of the film.

At the time of the reader, the scan case 23
Is stationary at a position behind the mirror 17 as shown in FIG. 1, and the image light of the microfilm F passes through the projection lens 15 and the prism holder 31 and passes through the mirrors 16 and 17.
Is projected on the screen 19 through the. On the other hand, at the time of printing, first, the mirror 17 is rotated in the direction of arrow c shown in FIG. 1 by a driving unit (not shown), and then the scan case 23 is moved in the direction of arrow d shown in FIG. 2 (preliminary scan). When the exposure start position indicated by the solid line is reached, the image light of the microfilm F is scanned on the photosensitive drum 24 via the print mirrors 21 and 22 while being reversed from the position in the direction of arrow e by a clutch means (not shown). Expose. The scanning exposure is performed until the scan case 23 reaches a position indicated by a two-dot chain line. After the end of the scanning exposure, the scan case 23 continues to move, and stops when it reaches the stationary position shown in FIG. After the scan case 23 comes to a standstill, the mirror 17 returns to the position where the mirror 17 forms the reader optical path. In addition, a one-dimensional image sensor (CC
D etc.), and a copy image may be obtained by the output of the image sensor and a laser beam printer.

FIG. 3 is a schematic perspective view of a prism holder 31 as an image rotation optical system. In the figure, a prism holder 31 holds an image rotation prism 32 and is supported so as to be rotatable around an optical axis.
Are integrally formed. And prism holder 3
1 is rotated by a stepping motor 35 via a gear 34 meshing with a gear 33. The stepping motor 35 rotates according to the amount of rotation given by the operator from the operation unit, and the prism 32 also rotates. Thereby, the prism 3
The image is rotated by the optical properties of 2. Further, a protruding piece 36 is provided on the outer peripheral portion of the prism holder 31, and a direction detection sensor 37 that detects the rotation of the protruding piece 36 and detects whether the prism 32 is in the reference direction is provided. ing. Then, when the projecting piece 36 rotates with the rotation of the prism holder 31 and blocks the detecting unit of the sensor 37, it is detected that the prism 32 has reached the reference direction.

FIG. 4 is a block diagram of a control system for operating the present embodiment. In the figure, the control circuit 41 includes:
An image rotation amount input unit 42 and a power switch 43 provided on an operation unit (not shown) are connected to each other, and further a direction detection sensor 37, a printer unit 45 for performing a series of image copying operations, and a stepping motor 35 through a motor driving circuit 44.
Are connected respectively.

[0012] The above arrangement of full of FIG 5 the operation of the present embodiment
This will be described using a flowchart. First, when the power switch 43 is pressed in # 1, the direction detection sensor 37 determines whether or not the prism 32 is in the reference direction in # 2. If it is in the reference direction in # 3, the image search is performed as it is,
At steps # 4 and # 5, an image exposure operation is started as necessary to copy an image, and the operation is terminated. On the other hand, the prism 32
Is not in the reference direction, the stepping motor 3
5, a driving force is applied, and the prism 32 rotates until it reaches the reference direction and a signal is generated from the direction detection sensor 37. Thereafter, an image search is performed (# 3). If necessary, an image exposure operation is performed to copy an image, and the operation is terminated (# 4 to # 5). Here, if the prism reference stop direction is set to the direction as shown in FIG. 10 described above, the movement direction of the screen projection image with respect to the movement direction of the image coincides with the left, right, up and down (front and back), so that the operator is most easy to use. .

FIGS. 6 and 7 show a second embodiment of the present invention. For the sake of simplicity, the same parts as those in the first embodiment are denoted by the same reference numerals, and only different points will be described. In this embodiment, a prism reset selection switch 51 for selecting whether or not to return the prism 32 to the reference direction when the power is turned on is provided.
1 connected. Other configurations are the same as those of the first embodiment. This corresponds to the case where the operator wants to temporarily suspend work due to small use, etc.
If it is not necessary to return the image whose inclination has been adjusted to the state before adjustment when it is desired to turn on the power again, the return operation may be deselected by the prism reset selection switch 51.

The operation of this embodiment having the above configuration will be described with reference to the flowchart of FIG. First, when the power switch 43 is pressed in # 11, it is determined whether or not the prism reset selection switch 51 is on in # 12. If it is on, the direction detection sensor 37 determines whether or not the prism 32 is in the reference direction in # 13.
Is determined by If it is in the reference direction in # 15, the image search is performed as it is, and in # 16 and # 17, the image exposure operation is started as necessary to copy the image, and the operation is terminated. If the switch 51 is off in # 12, the process proceeds to # 15. On the other hand, if the prism 32 is not in the reference direction in # 13, a driving force is applied to the stepping motor 35 in # 14, and the prism 32 rotates until it reaches the reference direction and a signal is generated from the direction detection sensor 37. Thereafter, an image search is performed (# 15), and an image exposure operation is performed as necessary to copy the image, and the operation is terminated (# 1).
6 to # 17).

FIGS. 8 and 9 show a third embodiment of the present invention. In this embodiment, a prism stop direction setting input unit 61 is provided so that the reference stop position of the prism 32, which is fixed in both embodiments described above, is variable, and further connected to the control circuit 41. Other configurations are the same as in the second embodiment. This is because, depending on the operator, the orientation of the microfilm image that is mainly handled differs (horizontal writing,
Vertical writing etc.), the familiar prism orientation is also different,
This allows the operator to freely set the reference position.

The operation of this embodiment having the above configuration will be described with reference to the flowchart of FIG. # 21 to # 24 and # 2
The operations of # 6 to # 28 are the same as those of # 11 to # 28 of FIG.
14 and # 15 to # 17, respectively, and # 21
After the prism 32 reaches the reference position by a series of operations in # 24, the motor 35 rotates by a predetermined amount according to the angle specified by the prism stop direction setting input unit 61 in # 25.
Thus, the prism 32 is stopped so that the screen angle can be obtained at an angle desired by the operator. Thereafter, the operations of # 26 to # 28 proceed according to the second embodiment.

[0017]

As described above, according to the present invention, when the power of the projector is turned on, the rotation of the prism is stopped in a fixed direction as a reference, so that the moving direction of the film and the moving direction of the projected image on the screen. Can always be kept constant, so that the operator can quickly search for a desired film image without confusion.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of a microfilm reader printer according to a first embodiment of the present invention in a reader state.

FIG. 2 is a schematic vertical cross-sectional view of a printing state.

FIG. 3 is a schematic perspective view showing the image rotation optical system.

FIG. 4 is a block diagram of a control system for operation.

FIG. 5 is a flowchart showing the operation procedure.

FIG. 6 is a block diagram of a control system for operating a microfilm reader printer according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing the operation procedure.

FIG. 8 is a block diagram of a control system for operating a microfilm reader printer according to a third embodiment of the present invention.

FIG. 9 is a flowchart showing the operation procedure.

FIG. 10 is an example showing a relationship diagram between a moving direction of a microfilm and a moving direction of a screen projection image by an optical system including a trapezoidal prism.

FIG. 11 is another example.

FIG. 12 is still another example.

[Explanation of symbols]

F ・ ・ Microfilm 、 15 ・ Projection lens 、 17 ・
・ Leader mirror, 18 ・ ・ Rotating mirror for leader, 2
1, 22, print mirror, 24, photosensitive drum, 3
1. Prism holder, 32 Prism, 35
Stepping motor, 37 ・ ・ Direction detection sensor, 41 ・
・ Control circuit, 51 ・ ・ Prism reset selection switch,
61 Prism stop direction setting input unit.

Claims (4)

(57) [Claims] 1. An image projection apparatus for projecting an image onto a screen and observing the image, comprising: an image rotation optical system in which an image rotation prism is rotatably mounted around a projection optical axis in a projection optical path; Driving means for rotating the rotating optical system, and when the power of the apparatus main body is turned on, the driving means rotates the image rotating prism to a reference stop direction and then stops. Image projection device. 2. The image processing apparatus according to claim 1, further comprising a switching unit and a selection unit that can select whether or not to rotate the image rotation prism to a reference stop direction by the driving unit when the power is turned on. 2. The image projection device according to 1. 3. A reference stopping direction of the image rotating prism is as follows.
2. The image projection device according to claim 1, wherein the direction of movement of the screen projection image with respect to the direction of movement of the image coincides with the left, right, up and down (front and rear) directions. 4. The image projection apparatus according to claim 1, wherein the reference stop direction of the image rotation prism can be switched to an arbitrary direction.