JPS6331266A - Picture reader - Google Patents

Abstract

PURPOSE:To require no memory for delay by inserting a double refraction plate of the thickness having its separate width equal to the distance between sensitive picture element strings to the light incident surface of a solid-state image pickup element, and simultaneously making reflected light from an original document incident on the solid-state image pickup element. CONSTITUTION:The light 3 is made incident on the double refraction plate 1, then, a double image having the separate width (d) is formed in the outgoing side. Therefore, when the original reflected light 3 of one line is made incident on the double refraction plate 1, it is irradiated on the image pickup elements 2 arranged to two strings. Therefore, the same original information is simultaneously made incident on the image pickup elements 2 of the two strings and the memory for temporarily storing the reading information of the original document as the conventional device is not required.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application in Industry) The present invention relates to a pixel reading device, and particularly to a pixel reading device with a simplified configuration.

(Prior Art) In a conventional image reading device, an imaging sensor (line sensor) in which photosensitive pixels such as a CCD are arranged in a long direction in the main scanning direction is used to photoelectrically convert document information. .

In this image sensor, in order to increase the resolution by -1-,
As shown in FIG. 3, two line sensors 11
, 12 are arranged in two rows by half a pixel in the longitudinal direction (X direction) and shifted by one pixel in the sub-scanning direction (Y direction). Further, by providing color filters 13 and 14 to the line sensor L shown in FIG. 4, a color imaging probe is formed.

In addition, since one long line sensor is expensive due to poor manufacturing yield, multiple short line sensors 15, 1
6, 17.18, dried as shown in Figure 5.
It has been proposed to arrange them in a strip pattern to perform the same function as a single long line sensor.

''- are arranged in one row with intervals in the sub-scanning direction. This interval is the same as in Section 3.4 above.
In the example shown, the sampling pitch is one pixel, and in the example shown in FIG. 5, the sampling pitch is approximately four. In the case of a 16 pixel/+nm image sensor, the former interval! is equal to the size of the photosensitive pixel], the spacing of the latter! In case (2), since one sampling pitch is 62°5 μm (-1 open/16), it becomes 250 μm.

(Invention or problem to be solved) The above-mentioned conventional technology had the following problems.

The above-mentioned conventional image sensor r- has a distance #I! in the sub-scanning direction. Or! Since they are separated again, using the image sensor -r-,
To read document information on the same line, the output information of the image sensor r in the first column 11 that reads the document information first is transferred to the second column 1.
] until the image sensor reads the document information on the same line.
It had to be delayed.

Specifically, conventionally, the above-mentioned delay has been achieved by temporarily storing the output signal of the image sensor in the first column in a memory and reading it out after a predetermined period of time.

Therefore, the conventional device requires a delay memory and also requires a control circuit for storing read information in the memory and reading it from the memory, making the circuit complex and expensive. There was a problem.

The purpose of the present invention is to eliminate the problems of the prior art described above,
To simplify the circuit configuration of a reading device and reduce its cost by eliminating the need for a delay memory.

(Means and operations for solving the problems) In order to solve the above-mentioned problems, the present invention provides an image sensor using a solid-state imaging device consisting of a one-dimensional photosensitive pixel row or a plurality of rows dfζ consisting of a plurality of photosensitive pixels. In the reading device, a birefringent plate having a thickness such that its separation width is equal to the distance between the photosensitive pixel rows is inserted into the light incident surface of the solid-state image sensor, and the reflected light from the original is reflected from the plurality of rows. The unique feature is that the light is incident on the solid-state image sensor at the same time.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of main parts of an embodiment of the present invention.

In the figure, 1 is a birefringent plate made of a calcite plate or a quartz plate, and 2 is a high-resolution image sensor similar to that in FIG.
3 shows the reflected light from the original.

Here, the properties of the birefringent plate 1 will be explained with reference to FIG. 2.

Now, when the thickness of the birefringent plate 1 is t and the direction of the crystal axis is A, when the angle between the direction A and the upper surface of the birefringent plate 1 is 45°, the light incident perpendicularly to the upper surface 3 has the maximum separation width d, and it is known that the relationship between the separation width d and the thickness t is expressed by the following equation.

d=tX (n 2 - n 2) / (2n n
)2 1 l 2 (1) Here, nl is the refractive index for normal light C, and n2 is the refractive index for extraordinary light 0.

In other words, when the light 3 is incident on the birefringent plate 1, a double image having a separation width d is formed on the exit side.

Returning to FIG. 1 again, the birefringent plate 1 has the properties described in I-, so when one line of reflected light 3 from the original is incident on the birefringent plate 1, the reflected light 3 is the birefringent plate 1
The light is divided into two parts by irradiating the image sensors arranged in two rows. Therefore, the same document information is incident on the two rows of image sensors at the same time, and there is no need for a memory for temporarily storing document reading information as in conventional devices.

In this example, the size of the photosensitive pixel is 7 μm.
Therefore, the interval between the image sensors arranged in two rows! is 7μ
It is m.

Therefore, the thickness of the birefringent plate 1 to be actually used can be found by substituting the value of ! into (1) in the above equation (1).Incidentally, the thickness can be found by calculation. and about 1
．． It will be 19mm.

- The explanation given above is an example in which the birefringent plates 1 are arranged in two rows in close contact with each other, but it can also be applied to the staggered arrangement of the imaging cables shown in FIG. it is obvious.

As described above, the present invention has the advantage that the memory used to temporarily store document information becomes less efficient.

(Effects of the Invention) As is clear from the description below, according to the present invention, reflected light from a document can be simultaneously incident on the imaging probes arranged in multiple rows in the sub-scanning direction. Therefore, there is no need to use a delay memory for temporarily storing read image information. Therefore, the circuit configuration of the image reading device becomes simple and can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the main parts of an embodiment of the present invention, FIG. 2 is an explanatory diagram of light separation by a birefringent plate, and FIGS. 3 and 4 are explanatory diagrams of a conventional high-resolution image sensor, respectively. Figure 5 (J shows an explanatory diagram of the imaging elements arranged in a staggered pattern.)...Birefringent plate, 2...Imaging cable, 3...Reflected light agent Patent attorney Michito Hiraki Outside 1 person Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 n”l-

Claims (3)

[Claims] (1) In an image reading device using a solid-state image sensor formed of a plurality of one-dimensional photosensitive pixel rows each consisting of a plurality of photosensitive pixels, a separation width of the light-incidence surface of the solid-state image sensor is An image reading device characterized by inserting a birefringent plate having a thickness equal to the distance between the two. (2) The image reading device according to claim 1, wherein the birefringent plate is a quartz plate. (3) The image reading device according to claim 1, wherein the birefringence plate is a calcite plate.