JPS605657Y2 - Original detection device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a document detection device for a flat scanning facsimile machine or the like.

Conventionally, there are known methods for detecting a document being transferred in this apparatus, such as a method using an optical sensor using a combination of a light emitting element and a light receiving element, a method using a micro switch, and the like.

However, these methods cannot be installed at the document reading position, and therefore a counter or the like has been used to correct the distance error between the optical sensor and the microswitch installation position.

Then, by detecting the leading and trailing edges of the original, control is performed to transport the original at high speed from the original insertion slot to the original reading position, and from the original reading position to the original ejection slot, or the leading edge of the original is brought to the reading position. When the document arrives, the document transfer motor is switched to control the document transfer speed.

However, in these methods, the distance to the document reading position must be corrected using a counter, etc. depending on the mounting position of the optical sensor and microswitch, so adjusting the mounting position of the optical sensor, etc. and the counter, etc. is extremely troublesome. However, the disadvantage is that errors are likely to occur.

Furthermore, it is not preferable to provide a special sensor or the like for detecting a document from the viewpoint of simplifying the mechanism.

The present invention eliminates these drawbacks and is characterized by detecting originals using a special pattern member and an optical reading head.The present invention is characterized by detecting originals using a special pattern member and an optical reading head. The purpose is to provide an unnecessary document detection device.

Hereinafter, the present invention will be explained in detail based on the drawings.

In FIG. 1, reference numeral 1 denotes a transmission document, which is transported in the direction of the arrow by a pair of rollers 3.4 rotated by a stepping motor 2. In FIG.

Reference numeral 5 indicates a pair of light sources such as fluorescent lamps that illuminate the document 1 being transferred in the sub-scanning direction, and 5' indicates a cover thereof.

6 is a condensing lens that collects the reflected light from the original 1; 7 is an image sensor such as a photodiode array; 8 is an amplifier; 9 is a binary quantization circuit that binarizes the image signal from the amplifier 8; 10 is a pattern detection circuit for a pattern described later, 11
12 is a counter circuit, 12 is an output terminal for a document detection signal, and 15 is a counter circuit.
is the output end of the image signal.

Further, reference numeral 13 denotes a document transport guide plate, and a pattern member 14 as shown in FIG. 2a is pasted on the reading position A of the guide plate 13.

This pattern member 14 is preferably formed by printing on the guide plate 13 in advance.

The pattern member 14 is repeatedly printed with a pattern 14a that does not appear on a normal original.

In this embodiment, the group indicated by h□ is one pattern, and this pattern n1 is regularly and repeatedly printed in succession with n2 . . . n□.

Next, to explain its operation, first, although not shown, when the original 1 is inserted into the original insertion slot, the original is detected and the motor 2 is driven at a very high speed.The leading edge of the original 1 reaches the reading position A. Maintain this state until.

In other words, until the leading edge of document 1 reaches reading position A,
The image sensor 7 reads the pattern member 14.

After the pattern signal is amplified by the amplifier 8, it becomes a binary pattern signal (FIG. 2b) by the binary quantization circuit 9, and the pattern of the pattern signal (FIG. 2b) is detected by the pattern detection circuit 10. Detect one group of patterns (
nl.

. . . nm) is counted and applied to the counter circuit 11.

When the counter circuit 11 counts the detection signal from the pattern detection circuit 10 five times, for example, it outputs it to the output terminal 12 as "pattern signal present (no original)".

Here, since a plurality of pattern signals (FIG. 2b) are repeatedly detected, there is no risk of misidentifying the information as information on the document 1, and the presence or absence of the document can be completely identified.

Next, when the original 1 is transported and its leading edge reaches the reading position, the pattern member 14 is covered with the original 1, so the information of the original 1 is applied to the sensor 7, and the information on the original 1 is applied to the sensor 7, and when the leading edge of the original reaches the reading position, the pattern member 14 is covered with the original 1. An image signal is applied to the pattern detection circuit 10.

At this point, no output is made to the output terminal 12 of the detection circuit 10.

The control signal from the output terminal 12 changes the speed of the motor 2 and controls the operation of the image signal processing circuit connected to the image signal output terminal 15.

The trailing edge of the document 1 is also detected in the same manner as described above.

As described above, in the present invention, a pattern member is placed at the document reading position, and when the optical reading device reads the surface of this pattern member, it is determined that there is no document, and when the surface of the pattern member cannot be read, it is determined that there is a document. In the apparatus for performing this, a plurality of patterns are written on the surface of the pattern member, and it is determined whether or not the surface of the pattern member has been read by detecting the number of patterns. It has the effect of

(b) First, since no special document detection means (e.g., microswitch or optical sensor) is required for document transfer, troubles such as document jams and skews can be greatly reduced, increasing the reliability of the device. It is possible to increase the efficiency and simplify the device.

(b) In addition, conventional document detection means such as microswitches and optical switches tend to malfunction because they detect the presence or absence of a document in one detection operation, but the document detection method of the present invention detects the number of patterns. (In the embodiment, the pattern member 14
(repeatedly detected five times), the document can be detected with extremely high precision.

(C) Furthermore, since the document detection of the present invention detects the number of patterns on the pattern member, the conventional method of detecting the integral value of the document detection signal (i.e., when a certain amount of signal is input from a state of no signal) The present invention can reliably detect originals even for reverse pattern originals (originals with white characters on a black background).

Additionally, in the conventional integral value detection method, there is a delay in detecting the original if the original has a neutral background color such as gray, whereas the present invention determines whether the original exists based on whether a pattern is detected. , even such documents can be reliably detected.

Furthermore, even if the width of the document is small relative to the effective screen, detection may be delayed or no detection may be performed at all because the input to the integration circuit is small; however, with this invention, the number of patterns is no longer detected. In this case, since the document is assumed to be present, accurate document detection is possible even in such a case.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of a document detection device according to the present invention. FIG. 2A is an enlarged plan view of the pattern member, and FIG. 2A is a waveform diagram of the pattern signal. 1... Original, 7... Image sensor,
8...Amplifier, 9...Binary quantization circuit, 10
...Pattern detection circuit, 11...Counter circuit, -n member. 14...Bata

Claims (1)

[Scope of utility model registration request] A pattern member is placed at a document reading position, and when an optical reading device reads the surface of the pattern member, it is determined that there is no document, and when the surface of the pattern member cannot be read, it is determined that there is a document. A document detection device characterized in that a plurality of patterns are written on the surface, and it is determined whether or not the surface of the pattern member has been read by detecting the number of patterns.