JPS5991412A - Image splitter - Google Patents

Abstract

PURPOSE:To form two optical images whose brightness is equal on the same face, by providing a prism which is symmetrical with respect to the face containing an optical axis of an image forming lens, in front of or in the rear of the image forming lens. CONSTITUTION:A triangular prism 202 which is face-symmetrical with respect to a face 206 containing an optical axis A of a convex lens 201 is provided behind the convex lens 201 being an image forming lens. According to this constitution, a point 203 on an original picture forms an image at each different position by the upper half and the lower half of the triangular prism 202, and two optical images 204, 205 are formed. The positions of this optical image 204 and 205 are changed by changing a vertical angle of the triangular prism 202. The smaller the vertical angle 207 becomes, the farther the two optical images 204, 205 are separated. Also, the two optical images 204, 205 are always formed on a face 208 being vertical to the optical axis A irrespective of size of the vertical angle 207, and the brightness of the two optical images 204, 205 is also the same.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image splitter that creates two optical images from one original image.

Conventional configuration and its problems Conventionally, in order to create two optical images from one original image, a semi-transparent mirror (1,02) is used after the imaging lens (IOI) as shown in Figure 1.
is arranged at an angle with respect to the optical axis (4) of the imaging lens (101), and an optical image (10
8) and an optical image (104) of the reflected light was obtained.

Although this method is simple, the optical images (108) (104
) is separated onto two optical image planes (105) and (106), and 2
Since the two optical images (108) and (104) are not on the plane perpendicular to the optical axis (5), the optical images (108) and (104)
This was inconvenient depending on the purpose of use because it was difficult to equalize the brightness of the lights.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an image splitter in which two optical images are on the same plane and the brightness of the two optical images can be made equal.

Structure of the Invention The image splitter of the present invention is characterized in that a prism that is symmetrical with respect to a plane including the optical axis of the imaging lens is disposed before or after the imaging lens.

DESCRIPTION OF EMBODIMENTS - Hereinafter, embodiments of the present invention will be described based on FIGS. 2 to 6.

FIG. 2 shows an embodiment of the invention. In Figure 2, after the convex lens (201) as an imaging lens, this convex lens (
A triangular prism (202) that is plane-symmetrical with respect to a plane (206) that includes the optical axis (5) of the prism (201) is disposed.

Because of this configuration, the point (20B) on the original image is imaged at different positions by the upper and lower halves of the triangular prism (202), resulting in two optical images (204) (205).
) can be done. The positions of the optical images (204) and (205) are changed by changing the apex angle of the triangular prism (202) (the angle between the equilateral sides of the isosceles triangle). As the apex angle (207) becomes smaller, the two light images (204) and (205) become farther apart.

Also, the two optical images (204) (205) have an apex angle (207
), regardless of the size of the optical axis (plane perpendicular to the station (2
08), and the two lights @ (204) and (205
) have the same brightness.

Figure 3 uses a V-shaped prism (802) in place of the triangular prism (202) in Figure 2, and a ■-shaped prism (
802) is disposed after the convex lens (801) as an imaging lens and is symmetrical with respect to a plane (806) containing the optical axis of the convex lens (301). Even with this configuration, the point (808) on the original image is a V-type prism (808).
The upper and lower halves of the light beam 02) form images at different positions 1t, forming two optical images (804) and (805).

The position of this optical image (804) (805) is changed by changing the corner (807) within the V-shaped prism (802).

The larger the angle (,907) is, the more these two light images (804)
and (805) leave. Also, as in the case of Fig. 2, the optical images (804) and (805) are always formed within the plane (808) perpendicular to the optical axis of the convex lens (801), and the two optical images (
The brightness of (804) and (805) is also the same.

In Figure 4, a focusing rod lens (401) is used instead of the convex lens (201) in Figure 2, and the triangular prism (402) is the same as the triangular prism (202) in Figure 2. . Because it was configured in this way, the original picture] second point (
408) is imaged at a point (407) when the triangular prism (402) is not provided, but the triangular prism (408)
02) is placed after the focusing rod lens (401), the point (40B) on the original image becomes the optical image (404) (405).
) and form an image. Two light images (404) (40
5) are both formed in a plane (408) perpendicular to the optical axis of the focusing rod lens (401), and the brightness of the two optical images (404) and (405) is also the same.

Although not shown, the triangular prism A (4
■ type prism (802) in Fig. 8 instead of 02)
A similar effect can also be obtained by arranging the converging rod lens (401) symmetrically with respect to the plane containing the optical axis.

In addition, in each of the embodiments described in Section 2, a triangular prism (202), (402), and a V-type prism (80
2), the same effect can be obtained even if it is arranged in front of the imaging lens as shown by the imaginary lines in FIGS. 2, 8, and 4.

In each of the above embodiments, the points (208) (80B) (40
8) are the optical images (204) (205) and (804
) (805), (404) and (405), but as shown in Figure 5, the optical image (504)
and (505) may overlap.

However, this can be achieved by arranging a screen restriction mask (507) shown by a virtual line near the original image (508). Mask (5
Triangular prism (502) to enlarge the aperture of 07)
This becomes possible by increasing the apex angle of and separating the two optical images (504 x 505). In addition, to be exact, the original picture (50
The point (508') on the optical axis of 8) is located between the optical image (504') and (
505') and the optical images (504'X505') are both imaged in a plane (508) perpendicular to the optical axis, but
For other parts of the area (504 x 505),
) is not included. Furthermore, the mask (507) in FIG. 5 can provide similar effects in the other embodiments.

FIG. 6 shows an embodiment in which the image splitter of the present invention is used in a line reading sensor head (600), in which a square prism (602) is disposed after a focusing rod lens (601). This line reading sensor head (60
0) has the same width as the original (608), and is configured so that one horizontal row can be read at a time.
The upper image point (604) is formed into two optical images (605) by a focusing rod lens (601) and a V-type prism (602).
(606), and these two optical images (605) (6
06) are semiconductor chips (607) (608) respectively
The photodetecting elements are arranged in a staggered manner in the width direction of the document (608) so that they are converted into electrical signals by the photodetecting element array (610) above, and the photodetecting elements are equally spaced without a break between the semiconductor chips (607) and (608). The arrays (610) are arranged side by side, and the interval B between the photodetecting element arrays (610) at the break between the semiconductor chips (607) and (60B) is the distance between the photodetecting elements in the semiconductor chips (607) and (608). Equal to the pitch C of the array (610). In the line reading sensor head (600) configured in this way, when the original image (608) is transferred in the direction indicated by the arrow, the signal obtained from the semiconductor chip (607) is delayed by a certain period of time and the signal obtained from the semiconductor chip (608) is delayed. When superimposed on the signal, one row in the width direction of the document (601) is seamlessly converted into a negative row of electrical signals even though a plurality of semiconductor chips (607) (60g) are used.

In such a case, conventionally the optical image plane (10
5) and (106) are semiconductor chips (607) and (608).
) had to be arranged separately, but by using the image splitter of the present invention, the semiconductor chips (607) and (608) can be arranged on the same substrate (609). This is particularly useful in manufacturing.

Although the line reading sensor head (600) has been described as an example in FIG. 6, the photodetecting element array (610) in FIG.
By using 08) as a photoreceptor, electrical signals can be converted into images using a known electrophotographic method.

It is possible to provide an inexpensive line reading sensor head and line writing head that can obtain an optical image with the effects of the invention.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional image splitter, Figure 2~
FIG. 6 shows an embodiment of the present invention, and FIGS. 2 to 5 are block diagrams of an image splitter according to the present invention, and FIG.
Figures (a) and (b) are a configuration diagram of a line reading sensor head using an image splitter of the present invention and a plan view of a photoelectric conversion section. (201) (801) - = convex lens (imaging lens), (
202) (402) (502)...Triangular prism,
(206) (806)...plane including the optical axis, (802
)...V-type prism, (401)...Focusing rod lens (imaging lens), (507) Screen limiting mask, (600)...Line reading sensor head, (6
07) (608)... Semiconductor chip agent Yoshihiro Moriki Figure 1 Figure 3 0B Figure 4

Claims (1)

[Claims] 1. An image splitter in which a prism that is symmetrical with respect to a plane containing the optical axis of the imaging lens is disposed before or after the imaging lens. 2. The image splitter according to claim 1, wherein the prism is a triangular prism. 8. The image splitter according to claim 1, wherein the prism is a V-type prism. 4. The image splitter according to claim 1, wherein the imaging lens is a convex lens. 5. The image splitter according to claim 1, wherein the imaging lens is a focusing rod lens. 6. The image splitter according to claim 1, wherein the image from the original image is received through a screen restriction mask placed near the original image.